I need to convert my 720p footage to standard def footage while still maintaining as much quality as possible. I don't know if its better to do it through quicktime, compressor, FCP, 3rd party software etc. And then when I export, do I need it to export with the black letterboxes or not? Thanks!
If you already have compressor then it should do a better job than FCP, you don't state what formats you are working with. If you want to spend some money on something, then there are a number of tools you can use that might do a better job, depends on your budget and the amount of time you are prepared to invest getting the best from them.
Please post back saying what solved your problem. It could help others, and saying 'thanks' is free!