Maybe take a look at "Milkshape" and see if that fits the bill? I use Hexagon for modeling, UltmateUnwrap3D for UV's and conversion, and Freeworld3D for terrains (well, still working on a good pipeline for that last one). But I do see/hear a lot of people swear by Milkshape.
^_^
"We've got a blind date with destiny...and it looks like she's ordered the lobster."
