i have an island in my kitchen, it contains the sink and the dishwasher. problem is that its not completely flat for the countertops. its a stepped island so it looks like this from the side

___
|....|__
|........|
like this:


like an "L" shape so that barstools are on the higher end. i want to 'chop' that higher end off and make it the same height all the way.

like this


im pretty sure i can do this myself. all i need to buy a bigger flat piece of corian. anyone do something like this before. i think i can go to homedepot and order one with custom dimensions or should i go find a countertop retail place?