Milkshape will allow you to make decent models, UV map them and even multi-sub-object texture them if your model requires more then one material to be used on it..
Export it out and import into XSI mod tool to handle the conversion into TF2 ..
collision mesh's made in milkshape3d must have the same materials assigned to them as the actual model even though the collision mesh will not be visible.
Also important to clean any vertex colors if you make selection sets by vertex color instead of groupings.