I second the opinion about not having equal size bowls. I went thru
about 2 weeks of sink hell trying to decide what to buy. I settled on
the Kohler Marsala, which is a cast iron/enamel sink with two bowls,
split about 70/30 or so. That gives you one bowl large enough for
pans, the other one still quite big and usable for collanders, etc. I
liked the idea of 2 bowls so you can have one clean and ready for
anything, while you use the other one for the main. IMO, the most
useless sinks are the ones that have one large bowl and then a smaller
disposal well. That's what I had and hated it, the disposal well is
just too small for any real use. And mine was installed with the
disposal on the main bowl anyway, which is where I like it. In fact, I
never knew until last week, that the small narrow bowl is really for
the disposal. I'd go with a 70/30 one or else one large bowl as a
second choice.

I like the Marsala also because it's a 2 hole model, with one hole
where the bowl divider is, the other in the right hand corner. That
leaves the area between the holes available so the basin on that side
can go back as far as the other larger basin, which has no faucet holes
at all. It gives you about another 2 inchs of fore/aft room. I have
the instant hot water dispenser in the corner, single hole faucet in
center. I made a mock up and compared this sink to others, like the
exec chef which is very similar, but doesn't have the extra 2 inchs.
IMO, it makes a big difference. Without the extra room, the smaller
bowl is still usable, but you'll always be conscious of the instant
water faucet being there as you go to put say, a collander, in it.
With the extra 2 inchs, it seems wide open.

As to material, it's basicly what u like and want to spend. Stainless
looks OK, without much work. If you really like it to shine, then it
does take more work. It also scratches fairly easy. It's resistant to
stains, but makes more noise with a disposal. Stone doesn't have a
shine and scratches/stains easily, but either of these can be remedied,
by, worst case, sanding it, as it's solid material. I chose Kohler
cast iron because I liked the look of the finish. It's advantages are
it doesn't stain easily, easy to keep clean, lasts a long time. Main
disadvantage is it can chip if you drop something hard on it and that's
hard to fix. It's also very heavy, if that's a factor. I looked at
Amer Std Americast, which is their steel/composite/enamel product.
It's about half the weight, but the finish just doesn't look like the
rich, quality of Kohler cast iron. If you go with stainless, people
I've talked to like Franke a lot.