If you just want the commentary, Rowman's Definitive Edition extras has just the parts of the movie with the Definitive Edition commentary. The commentary isn't very long, and is silent for most of the films anyway. But they do have some interesting things to say. Rowman's extras disc set is worth getting, because it has all the extras from the laserdiscs, and much more.

It was also included on the Dr Gonzo set, and cowclops v2. There may be some other sources, but those are the only ones I know of.