A lot of people really love their Kohler ledge sinks. I don't know much about the Elkay, but they are usually pretty good on pricing. It probably won't matter whether you order a Kohler at a big box store or a plumbing store as far as the metal is concerned. All Kohler sinks are manufactured by the same facilities, and Kohler is not transparent about their sourcing of metal, so it could be recycled for all we know. There are some reports specifically from @StarCraft Custom Builders about different models of Kohler faucets being of higher quality from plumbing stores than from big box stores, so watch out on the faucets, but I've not heard of such discrepancies with the sinks.

You'll find many people, even some pros, avidly debating the risk for rusting of stainless steel (some will argue that stainless steel can never rust, which is incorrect), but do your own research here in the Houzz forums or on Google, and you'll find people who have had rust issues with stainless steel sinks as well as technical publications that talk about rust and the factors that affect it. Any stainless steel can rust if not properly cared for, and the degree of risk has to do with the alloy composition and purity which can vary among metals labeled "stainless steel."

You asked for recommendations of other brands to consider, and a few companies that use non-recycled and salt-resistant 316 marine grade of stainless and manufacture in North America are Havens Metal, Julien, The Galley, and Rachiele, but you'll pay a premium for all those brands. Lesser quality and also less expensive would be Create Good Sinks, but they manufacture in China with nontransparent metal sourcing, still great sinks, but if you can budget more and plan to live in the house a long time, then spread your shopping net a little wider.

If you get any more comments on this thread, I can guarantee you there will be some heated debate. People are pretty passionate about their own opinions on sinks. I personally did my research and picked Havens Metal in the textured Prestige finish because it was the best value for the features, I liked the shape of the accessories, the textured finish that hides scratches and water spots was appealing to me, and I wanted an apron-front, which they offered as a standard style.

Over several years, I've installed hundreds of Kohler stainless steel sinks, manufactured in Mexico, and have yet to get a single complaint of rusting.

I installed a Kohler prolific 2 years ago. My thoughts after two years of use are:

*Wish it were longer 6-12 inches. When you have the accessories on the ledges, the sink gets too small.

*As it is an 18 guage, vs 16 guage, it scratches much more often and easier than my other stainless sinks, (I have 4 in my kitchen and bar area). I knew it was not a 16 guage when I purchased it and almost did not get it because of this, but decided it might not make that much difference, It definitely does!

*Wish they made the drying racks 1/2 the size they are.

I like the sink, but knowing what I know now, I would have purchased a larger sink.

“*It does scratch”

All stainless steel sinks scratch, regardless of brand, regardless if you spend $400 or $4000. The scratches blend into a patina over time, and you don’t notice them. Anyone who does not want scratches in their sink should not get a stainless steel sink. Consequently, scratches should not be a deciding factor in the OP’s decision of the Elkay or the Kohler.

OP - both sinks you mention are good. As mentioned above make sure you are comfortable with the interior space of each sink. You don’t say what size you need. Me, I have no use for the inserts. I prefer my separate colander and cutting board, and that’s me. So if it were me, I’d consider the Elkay Crosstown 31-1/2” sink because the corner drain sets it apart. Once you have a corner drain, you’ll never go back to a center drain.