You could go with either size, it all depends on what you like best, there is no right or wrong. I have an 18" wide linen cabinet going on the left side and then 48" of counter top. Yes, it's the 21" standard depth. I measured it and there is 3" in front of sink (of counter) and 4" from sink back to the coved backsplash. I had my sink undermounted in a corian counter top. I like the integral sinks but the white corian always looks dull and dirty to me so I wanted a china sink. Don't forget to consider your faucets if you go w/ the larger sink since there's not alot of room between the backsplash and sink edge. I got a 4" mini spread and there's plenty of room to clean around them. If you go w/ the smaller sink, I'm sure it look fine, too. I almost went w/ the Ladena which is rectangular, check that out also.

@Laura517: I'm not Bee, but I've had great luck shining Chrome with a slightly damp Costco paper towel. Also works great for a streak-free shine on glass! As long as you don't get lime scale, easy peasy. @beekeeperswife: your Brizo Solna looks identical to my Delta Trinsic! I've seen similar looking faucets, but this is ridiculous! Even the spray pattern is identical.

I just purchased the corstone edgewood self rimming sink, has a really nice drainboard and is deep. I think its very practical if you scrub or spray and wash so you do not have to make the counter top all wet, water just drains off the drainboard nicely. It also looks very nice and expensive. I really liked the kohler glen falls laundry sink, but it was around $500+, so I picked this one up at wayfair for $160! It looks a lot like cast iron imho!

mgs makes super high end faucets. Margie B has one in her beautiful kitchen (link below). Perhaps you can contact her for a reference on the brand. They are made in Italy and are completely stainless steel, which is what drives up the price. KWC has super quality but not all of their faucets have pull downs with spray. The Sin has 2 different faucets with spray and "automatic diverter reset". A third has only pull down with aerator (no spray). So question is whether first two switch from aerator to spray and stay on either way? I used their Systema and loved it but found it only when I called them for suggestions. They were really helpful. Here is a link that might be useful: Margie B's kitchen with MGS Faucet