Video workflow?

I want to put a soundtrack to video. Sonar has only limited formats that it works with AFAICS. So I was wondering. To avoid too many conversions, my immediate thought is to import an avi of moderate frame size and quality, to keep resource use down while scoring, then take the soundtrack and drop it back to my video editor, then export to my chosen format from there. This seems sensible, but I know there can be gotchas with sync etc. So has anyone any other ideas or hints? Thanks for any help