I've gotten Wilsonart sheets through a countertop place a few times. They could get me anything I wanted in a couple days or so, but it was definitely not at wholesale prices. I paid about $50 plus tax for each 4x8 sheet. I'll probably try the distributor route next time to see if I can get a break there.
Regardless even if you end up going through a place like Home Depot, it may be worthwhile to check out a countertop store for a different reason - they usually have a whole rack of sample tiles (little 2"x3" pieces or such), usually much more extensive than HD if they even have it at all there. Not only can you check out the colors and textures, but each tile has the order/part number on a sticker on the back. Once you can specify exactly what you want with that, it is a lot easier to call around and get prices.