i think savvy is getting confused. the OS doesn't sit in RAM, it sits in ROM. ROM is like the harddrive, and it only uses 2 megs of active RAM for the OS, so you still have 30 megs to play with.
i wrote a much longer thread earlier on, and pm just gave me an error, so basically it said 3630s are good, get one, and then wait for one of the new xscale ppcs to come down in price.