I remember seeing a couple of sites that allowed you to buy a set of plants based on what region you would lke to replicate and on volume, but I can't remember them. I didn't have too much success with google either.
Check out the links at the bottom of our forum here. There are several sites called "Sponsors" there that most assuredly will have what your looking for. Also I have found that a lot of plant sales sites can, and will, be glad to put together a group of plants conforming to your "specs" if you talk to them or email them before placing an order.