[AlexLakis]

I'm afraid it's the operating system limiting your RAM usage, not Pro Tools. If you wanted to give more RAM to Fruity Loops and use it at the same time as Pro Tools, you'd have to build two separate computers and run a 64-bit operating system on the Fruity Loops one and basically treat it as an outboard processor (alternatively, if you didn't need to run them at the same time, you could install both operating systems on the same computer and duel-boot-swap between them as needed.) This is, of course, assuming that Fruity Loops is compatible with a 64-bit operating system, which I'm completely unsure of.

Indeed, it may prove expensive to build the original Quadzilla since a few of the parts may be hard to find these days...Again, why not go for the Intel? If you're concerned about getting "the most for your buck," it would seem the logical way to go?

Also, to re-emphasize sentiments from the sticky threads, changing even what one may consider to be a small detail about the build opens up a whole slew of potential problems. RAM, video card, even power supply can render the build completely useless for Pro Tools (she's a fickle mistress!) So, if you elect to modify one of the builds, do as much research as you can and see if you can find others who have made the same modifications and find out how it has worked out for them. Otherwise, you're on your own, and it will be much more difficult for the community to help you troubleshoot should problems arise.