Oh, and for what it's worth, keep a close eye on craigslist. You'd be amazed at what you can find for kitchen cabinets. From "wow, you really need to update this kitchen" to "my husband makes so much money that I'm not satisfied with the 3 year old beautiful cabinets. I want custom exotic wood cabinets and viking appliances and..."
You could get a handful of really good quality lower cabinets, a sheet or two of furniture grade plywood for the back or sides, and have a huge variety of options for the countertop. Simplest: plywood or (whatever the heck that particle board stuff is), with formica top and edges. The formica would require a little use of the router. Or, plywood, then cementboard & put tile or 1'x1' granite squares on it.
Going this route would give you the greatest number of options & cost the least. If you had a sink base, & were handy with plumbing, you could put a sink into the island. Or a cooktop.