I'm trying to drum up a commission for someone to do this for me, but in case I can't, I better get to work!

I need to make some maps (I'm using MapTools) for a DnD session next weekend. I want to make some 24x36 (1" = 5') battlemaps of an oak forest in the fall.

Does anyone know where I can find a pack of top-down trees and fallen leaves?