Cleaner is kind of an expensive alternative to QT pro, but if you can't wait, then it will give you decent mpeg encoding. The straight version only does CBR, so if you are looking to get fancy, you'll need to do the Charger (OS-9 and Classic only).
You can get a quicktime plug-in for mpeg from Heuris, and I think it is not too expensive. Plus, for the price of cleaner, I think they have a dedicated MPEG suite that has more options than straight Cleaner.
Look at this thread. I blew my forum wad on this topic already.
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