Forgot to mention that we plan to have another trash can under the main clean up sink.

Most people prefer the dishwasher to be to the right of the sink, but it also depends where your dish/glasses storage is.

I'd recommend that the prep sink go on the end of the island closest to the cooktop. Trash? Probably immediately next to the prep sink.

As for the sink cabinet width, it depends on your sink. If you don't know the size of your sink, probably best to go for a 36" cabinet.

One other suggestion. I found 12" drawers to be pretty useless (although I think it's a great idea to create a cabinet in the space where you wrote in "12" stack of drawers" in the island. One of my favorite cabinets in my previous house/kitchen was the cabinet dedicated to the step stool. Ours was 9" and it was extremely convenient.

Thanks! I was thinking of putting dish towels in the 12" drawers. Think it's too small for that use, too? If so I may steal your idea...

It's certainly better than nothing, but I found the top drawer of a standard 12" stack was too shallow (basically, two oven mitts couldn't be stacked). If it's a 3-drawer stack rather than a 4-drawer, that might be better.

Just wanted to say that I am right handed and it is more natural to me to have the dw on the left side of the sink.

What about balance / symmetry? I am leaning towards (from left) 30 in cabinet for Advantium, then another 30 in, then 36 in sink base w open shelves above and the end w 24 in cabinet above dishwasher. Should I be concerned about symmetry above?