your speed has nothing to do with the pixel rate you want to run.
I run my Hero 2 at 720p for my videos... I don't see any real benefit to running the 1080 except larger file sizes.
The framerate is where your speed comes into play. I find that 30 fps makes pretty good video... though it's a little jerky in transitions.
Anybody know of good software to edit the videos in? I have ways to edit, but they're a complete pita.