Thanks for the bump. I had done a little searching after Am_I_Evil mentioned it might not be possible for a widescreen version but forgot all about posting it. I did find confirmation that the Buffy series wasn't shot in widescreen.
Talking about Whedon...
He kiboshed plans to release “Buffy the Vampire Slayer” in widescreen, because it was never shot widescreen. However, for the Sept. 2 release of Angel Season Two, Whedon approved widescreen presentations.
“‘Angel’ is a widescreen show, starting with the second season,” Whedon said. “So that is presented widescreen.”