I use QTPro to import SD video footage from my camera as h.264, but there's no way to adjust or add to the capture presets. I have three: Mpeg-4 (Good) h.264 - 320x(better) and h.264 640x (best)

They work okay, but I'd like to make my own. Is there a prefs, plist, or other config file I can edit to add more options?

This capture method saves me a ton of diskspace (350megs vs 11gigs) and it looks great for what I'm doing. Wouldn't recommend it for precision editing, tho.

AFAIK there is no way to add your own. Have you tried using iMovie? Perhaps it has some custom import settings.