[pezguy]

First like AlekLakis stated use a proven stable build and spend a little extra money. Using a non standard configuration will only end up causing extra hassles and problems. Been there done that. The Intel spec at this point will give you the most bang for buck.

64 Bit Vista and ProTools are not compatible at this point and for the foreseeable future. There are many threads on this subject as well. The bottom line is that you will have to use either Vista 32 or XP which will cap your memory usage at 4GB.