thanks! most of them hover right around 27 inches and basin size between 25-26

For me, out of those choices, the Kraus would be my choice. The reasons are that (1) it is 16 gauge, while the Elkay and Franke are 18 gauge. Some people don't think this makes a difference, but I do. (2) The Kraus has the corner offset drain. Once you have an offset drain in the corner, you'll never go back to a center drain. A corner offset drain means you can set large things down in the sink without covering the drain, and also there is more space under the sink for storage because you don't have the drain pipe right in the middle. (3) The Kraus appears to have interior dimensions of 25" x 17". The Elkay for example has interior dimensions of 24" x 16" - why forego 2", every inch counts. I have not checked the other sinks' dimensions, but you should, and make sure you are looking at interior dimensions. Re the Ruvati, I have heard mixed reports about that drain style, some people love it, others do not.

As to scratching - all stainless steel sinks scratch. If you do not want that, then you need to switch your sink material choice. The scratches blend into a patina after a while. The first couple scratches are hard, and then you don't notice. But if you know that scratches will bother you, choose instead a sink of granite composite or enameled cast iron.

As to rust - stainless steel does not rust. When people report their stainless steel shows rust it is from something left in the sink that rusts. A metal spatula, a can top, or the worst culprit is people use steel wool pads to clean their sinks which they absolutely must not. The steel wool pads leave behind tiny particles which themselves rust, not the sink. Another culprit - which is what I deal with - is water that has a lot of iron in it, and when the water droplets dry, the orange-brown marks of the iron are left behind. All this is easily cleanable with Bar Keepers Friend and a sponge.

I'd pick a 30" undermount with a 28" interior width. In many cases the sink can drop into the space between the cabinet sides with the rim resting on the top sides of the cabinet. You'll need to measure everything for this installation. When it fits you can ignore the minimum cabinet size recommendation. You don't need any added mounting system. And your counter to sink joint will never open up.

@dan1888 - my countertop people told me that with a 30 inch base i should go with 27 inch sink.... would love to hear more about this! Obviously would love to max my sink out as much as possible!

Im just going to park myself in this thread and learn too, if you dont mind.

My sink base will be 33” so I had settled on the Kraus Standart Pro 30”, but if i can get away with a 33”….

I just measured inside my 30” base cabinet and its 27.5 interior so

no way basin can exceed 27

"my countertop people told me that with a 30 inch base i should go with 27 inch sink...."

Your countertop people are mistaken. A 30" sink undermounts in a 30" cabinet, no matter what the sink manufacturer says as long as you strap the sink in place and throw their junk clips in the trash.

"In many cases the sink can drop into the space between the cabinet sides with the rim resting on the top sides of the cabinet. You'll need to measure everything for this installation. When it fits you can ignore the minimum cabinet size recommendation. You don't need any added mounting system. And your counter to sink joint will never open up."

The top of a cabinet is a very poor method to hold a sink in place. Unlike a strap system, cabinet sides are unable to exert pressure on the bottom of the sink, pushing the sink flange against the bottom of the stone. You absolutely need an additional mounting system such as a Hercules Universal Sink Harness from BB Industries or a Sink Strap or two from GranQuartz. Pete's Sink Mount for the heavies.

Thank you @Joseph Corlett, LLC -- i measured inside cabinet and it's 27.5.... so as long as i have a basin of 27 or so it should fit without an issue...?

For example, the Blanco Stainless 28" says 33 minimum cabinet....but basin is only 26 (my cabinet interior width is 27.5)....

https://www.build.com/blanco-441024/s205235?uid=1123788

@Joseph Corlett, LLC

"so as long as i have a basin of 27 or so it should fit without an issue...?"

Correct. I've put 33" sinks into 27" cabinets.

But is this sometbinf that is totally confuse my countertop guy/contractor? haha

All the strength of a cabinet is contained in the side material. That's what holds the countertop weight up. So the sides exert all the force upward on the countertop. When you sandwich the sink rim between the heavy counter material and the cabinet side there's zero extra space if the cabinet side tops are all installed level. No possiblity of any space opening in the future.. But this installation happens when the counter is installed. Not after unless you have extra space or maybe cut the sides. The sink measurement you need to fit in your cabinet will be a bit more than the interior dimension of the sink listed by the manufacturer. I'd measure an example in person. If the sink rim rests on the cabinet sides you can always strap it if you want added protection. You do benefit from an accurate cutout.

"When you sandwich the sink rim between the heavy counter material and the cabinet side there's zero extra space if the cabinet side tops are all installed level. No possiblity of any space opening in the future.."

Good theory, little real-world relevance.

First, the sink flange would have to be rabbeted into the cabinet tops perfectly flush. Secondly, tops aren't the exact same thickness throughout and nearly all have to be shimmed somewhat. That means there will be a gap the thickness of the shims between the sink flange and stone bottom. That means an uneven silicone joint and on the recommended slight positive reveal that won't look good. When a sink is pushed against a stone bottom by straps, the gap is tight and consistent no matter what the shims are doing.

Furthermore, if the sink ever has to be replaced, it's now much more difficult because the cabinet sides have to be unzipped to get the sink out and reinstalled to get the new sink in. A strapped sink is replaced in little over an hour by backing off two bolts.

Using cabinet tops to support sinks is not good practice.

Thank you again @Joseph Corlett, LLC - have found your posts here on Houzz so helpful in my wild sink research over the past couple days.

Spoke with my countertop people and they said they usually use mechnical brackets for a larger sink (where basin size is closer to interior cabinet width)....

You don't say what your countertop material is, but the installation of mechanical fasteners into engineered stone voids the manufacturer's warranty. Clips are junk and leak. If they put them along the front rail, it makes the rail too fat, so they usually just skip them which can endanger reinforcing steel in natural stone tops.

Insist on a strapped sink please. It ain't all that.

Shimming, if necessary, wouldn't be on top of the sink flange. It would be on top of the cabinet sides. The goal is to lock the sink against the bottom of the counter. You engineer the installation to accomplish the goal. . . .A single bowl stainless sink is a very, very low probability item to be replaced. I'd not design for that probability. Cabs and counter are more likely. The installation method is not ordinary or the easiest for the counter fabricator. It requires care and skill.

Oh so good to know @Joseph Corlett, LLC - will ask about this thanks!!

(Countertop will be quartz ) @Joseph Corlett, LLC