All right :) Personally, I always crop to what the majority of the footage is sized. So for if the majority of your clips are Buffy, I'd do fullscreen. If the majority is Angel widescreen, then do widescreen. I just tend to do that because you need to adjust every clip that is different from your project to fit the project. The way you achieve that inside Premiere is with the pan and crop feature. That effect is listed in the transform section of your effects. Just play around with that a little and make sure you have the "keep aspect ratio" ticked, otherwise you get sticky people ;)