Thanks for the help guys! I downloaded Super and Movie Maker, and I'll see what happens.
Using Super, I noticed that, encoding to AAC, it won't let you choose anything higher than 256kbps. However, if I switch to AC3, it will. The YouTube information link that Kraco provided says to use AAC-LC, but to set the bitrate to 48 or 96. I don't know enough about encoding to know the difference, so I'm going to try what YouTube recommends first.
EDIT: Movie Maker apparently doesn't support AAC files. Guess I'll try AC3 after all.
EDIT 2: That didn't work either. Fuck it, keeping it as a WAV file.