Doesn't Terragen give you a heightmap?
Yes, but it does procedural (perlin, etc.) terrains - no really good way to "design" your map.
As for splatmaps, in the process of finding out what they are I came across this. Not sure if that's what you're after.
I'm the author of a toolset for Unity that makes importing splatmaps easy. I also know how to generate them in TG2. That part is easy. Placement is a bit more difficult if you don't want it 100% procedural.
I've asked a guy I know from the Games Design course at my uni if he can supply/create any, he's pretty good at low poly work. He'll probably just want crediting for it so it can go into his portfolio/CV. Here is his stuff.
That'd be fantastic. I wouldn't even mind paying a few bucks for good models - but there is nothing even close to what I need on the market, at least nowhere I looked.
