To me, your option #2 seems the easiest and least disruptive. And I'd get a disposal in both sinks, so that you don't limit veggie prep just to your main sink.

What kind of sink was the 10" deep one? Was it stainless, silgranit, fireclay? What shape is it?

Are you undermounting the sink? If so, I've found that my 8" fireclay farm sink is plenty deep enough, and my 10" prep sink is actually a tad too deep to be comfortable. (I'm 5'7", albeit with Neanderthal arms, for reference.)

So I'd also go for option #2.

Thanks for your postings thusfar. Sink is stainless undermount with matching stainless undermount for island. Sink is brand new not even out of plastic yet. The only 8" sink I could find was a double bowl sink - and I had really wanted a single bowl sink. I did see some 9" single bowl sinks, but I think I would still need to lower the drain - so not really worth it. Dear hubby said rip it open and he will fix it on Saturday (giving up his golf game!) We have already blown our budget and a farm sink is too expensive especially since cabinets are already on order. Thanks so much for your thoughts and suggestions!

Here is a link that might be useful: Mr Direct Sinks

My sinks are reversed -- 8" prep and 10" main. The 8" is good for the prep sink, but I will not part with my large, deep sink. I'd lower the drain. How often are you going to do this? How often will you use it once it is done?

8" deep should be plenty roomy. I vote for #2, the popular vote ;)

When I ran into this problem:
I cut out a hole in the cabinet back about 12 by 18" high. Doesn't need to be neat but stay 2" away from sides and bottom of cabinet.
Cut off the drain pipe about 5" below the existing Tee connection.
Glued on a new Tee.
glued a ~6" piece of pipe and coupling to connect to the outside cleanout located at the top of the drain pipe.

Cut a neat square piece of 1/4" birch plywood to cover the hole in the cabinet. sanded edges and spray can varnish job. and of course a hole for the new drain connection.

Attached the plywood with 4 screws at the corners.

Took about 1/2 day altogether. It's a little cramped working under the sink.

Don't compromise on getting the sink you want just because it's a little work. It's very difficult (impossible?) to change an undermount sink later.

Option 2 is the best - but option 1 will also work - of course a DW can drain directly - some locales don't allow disposals.

I agree with Sabjimata. Option #2 is the least stressful option, and 8" + your counter thickness will make a 9" deep sink which is plenty deep enough. Elkay makes a number of 8" deep single-bowl sinks in a similar size as what you've linked. I'll link to their website. Use the search function at the top of the Elkay page to sort for single bowl and length of sink. While it won't sort specifically for 8" depth, it will sort by depth shallow-to-deep, so you can find an 8" deep sink that way. And if you find a model you like there, google for a good price for it on the internet. The MSRP prices listed on the Elkay website are waaay more than what they actually cost through internet sellers.

Here is a link that might be useful: Elkay website undermount sinks

WARNING...one of the mistakes I made in my kitchen is the location of the one garbage disposal...it's on our main/cleanup sink and not the prep sink. It turns out that it would have been better to have it on the prep sink than the cleanup sink. When peeling veggies, etc., I have to either go to the cleanup sink or manually clean out the prep sink and take the peelings to the cleanup sink.

Ideally, both sinks should have a GD, but if only one does, I recommend you make it the prep sink.

It's not that difficult to remove the drywall and correct the problem. That's the option I'd choose. I'd never give up a deep sink over such a minor issue! BTW, I'd also put a disposal on the prep sink.

And, plumbing codes prohibit the discharge of a DW directly into a drain--which means the drain line in the wall or the waste arm going into that wall. Now, if you use the special attachment that hooks onto your sink tailpiece that is before the sink trap, that will workand is up to code.

I'm happy with an 8" deep undermount cast iron sink without disposal. I'm 5'6' and would not want the sink deeper. I mulch the considerable vegetable/fruit scraps from the garden and would not use a disposal if I had one.

Look at some of the 9" deep sinks, Artisan makes some and they are very good quality. Perhaps this and a "compact" disposal might solve the problem.

I totally agree with LWO. Fix it now. Consider time and money as well as having the kitchen you want. It will not be free to return ship a sink and get a new one. How long will it take to find a new sink, return the old one and have the new one delivered? If your DH will replumb this weekend, that is probably faster and you have what you wanted. Just do something really nice for him :)

The best sink for the GD depends upon how you handle food scraps as well as how you prep. Do you compost, peel directly into the sink, scrape dirty plates into the clean up sink after dinner? The majority of my food is scraped in the cleanup sink. If the GD were in the prep sink, it would be a BIG hassle.

If I really wanted the GD, I would have them fix the plumbing problem for a couple hundred $. The plumber will take about 2 hours to this. $75 to $100/hr, that is not that much. You don't even have to do the finish work on the dry wall since it will be covered by the back of the cabinet.