[G4] Sawtooth processor

[E Koballa]

I'm quite a tinkerer with my g4 Sawtooth, I've upgraded the ram and a 
few other things.  I'd like to boost the processor (preferably 500mhz 
or more) for several apps.  My biggest restraint is my budget, I am 
saving to buy a macbook this coming summer.  I don't plan on selling my 
sawtooth, but rather to use it for printer sharing, file storage, and a 
computer for my girlfriend to use at my house.
The root of the question is... 500mhz processors from sawtooths cost 
quite a bit more than most from digital audio g4's, what kind of 
modification am I looking at to use a digital audio or other processor 
with a sawtooth.

Evan