How do you feel about a round prep sink? If you want to mount your faucet off the side a bit, I think a round one would be your best bet since you say the Kohler 5-sided is out.

Ticor has a round sink, 16" diameter, interior, that meets your criterion of being Specs:

* Brand: Ticor
* Model: S905
* Installation Type: Undermount/Overmount
* Exterior Dimensions: 18-1/2" Diameter x 7-1/4" Deep
* Interior Dimensions: 16" Diameter x 7-1/4" Deep
* Drain Opening: 3-1/2" Standard
* Material: High Quality 18/10 Chromium/Nickel Stainless Steel
* Sink Gauge: 16-gauge
* Finish: Brushed Bowl/Polished Rim
* Minimum Sink Base Cabinet Required: 21"

* Features: Heavy Duty Sound Guard Coating and Padding
* Scratch-resistant Top Mirror Finish

* Included With Sink As Free Items: Template for Sink Cutout
* Mounting and Installation Brackets
* 1 Rinse Sink Grids (Polished 18/10 Stainless Steel Wire Bottom Grid with Opening for Sink Strainer)
* 1 Deluxe Strainer

FYI...I have a Ticor S405D as my main sink and I couldn't be happier with it...it's a great sink and I love the SS sink grids (my Kohler 5-sided only has a vinyl-coated grid available...and the grid has already stained some; my Ticor grids, OTOH, look like new!)

Here is a link that might be useful: Ticor S905 Undermount Overmount Stainless Single Bowl Kitchen Sink

Ours isn't stainless, but is rectangular/almost square. We have ours on the corner of our island and just mounted the faucet off the inner corner, so that either side can be the 'front.' You don't have to have a 5-sided sink to do that...It should be especially easy to make look nice with an undermounted sink without the exposed edge to deal with.

I thought I posted last night but it isn't here. Ours is similar to rhome's except that we have a little more counter to the outer edge of the sink. We have a roughly 16 inch square centered in a 30 inch cabinet (didn't go larger because the cabinet is only 21 inches deep -- another reason we went off to the side with the faucet). Our island is not as wide as rhome's and we wanted a landing spot with the fridge and ovens near that end. We did a slight arc across the ends of the island and that makes the landing area just a bit wider. We went back and forth on where to put the faucet and decided on the outer corner since that left the inside part of the sink more open to someone working from the other side of the island. Not sure it would have made that much difference, but it is working as is.

Are you going to have a side by side ref?

If you are, there's a special problem you might run into. With a side by side particularly in your orientation, you pretty much can't sit things down on the counter to its right because the ref door blocks it. This isn't a terribly huge issue, but it can be irritating because you can't just turn around and sit things down because of the position of the prep sink.

It will still be irritating to try and put things down beside the prep sink - I think the door won't open wide enough to make that nice to do - when you have a large thing, you'll probably need to close the door or walk around the outside of the island.

If its a french door, the same thing happens but their doors are a little smaller, its a little bit easier to maneuver around them.

I'd probably still find it irritating. I'd rather trade the prep sink cabinet and one of the 36" cabinets beside it. Or buy a single door ref.
Ymmv

Buehl,
I have considered a round sink and I think it could help a lot. I was a little concerned about the splashing with a full-size faucet. I need to read more about the opinions on round sinks.

Rhome,
Thanks for explaining your pic. I found it in the blog and couldn't quite figure out how the faucet was placed. This is helpful since I always assumed it would have to be mounted on the corner. The could be a great solution!

Lascats,
So you don't get splashing with the faucet mounted on the outside edge? One of my reasons for moving it to the inner corner was that I don't have much landing area. Sounds like you have more than I'll have, though.

bmorepanic,
Thanks for pointing that out. I hadn't thought of it. It will be a standard FD fridge. I'll need to play with it a bit tomorrow when I'm on the jobsite. I really need to set up some cardboard boxes so I can "walk" and "work" around the kitchen.

Thanks for all your input--It helps to see that I wasn't doing something "wrong!"

I have about 7-1/2 inches to the side of the cabinet and then over the end panel and with an little more overhang, it goes from 9-1/2 inches to about 11 to 11-1/2 inches. You could get a similar placement if you moved yours to one side rather than centering it. If you have room and like the idea of giving a slight arc to the ends of the island, you'd be about the same as mine. My fridge opens up so that my landing spot tends to be behind the sink more than beside it though.

I can get a splash with the new faucet if we turn it on high and especially if you put your hands up high. It takes once or twice to remember to wash them or hold things lower. The main issue with water is what drips off our hands at the faucet and I have learned to do better with wrist bumps.