Ah, hello.

I've been having trouble lately obtaining a copy of 3D Studio 4.0, the download for older versions aren't even offered by Discreet.

Also... -this is the question- Is 3D Studio the only 3D design program compatible with Morrowind?

I appreicate any assistance that anyone may provide.

Exactly right. The export plugin is for 3dsmax only.

Yup, like Peregrine said. But there is a way to export and Import .NIF files using other programs, but it tends to get more complicated. But if you really feel like using something else then check this out. It really helped me.