i am an avid mac user as well but this iooks like fun so i have decided i am going to throw down like 800$ and get a dedicated PC setup solely for the emulator-x. kinda like how some people run giga on pc's i guess...
i just broke down and bought emulator x studio for my athlon xp 2000 box. going to sequence it from my powerbook running digital performer.
plan to also build a dedicated box for it, so i can get a lot more performance but also 16 tracks total from it at a time (2 windows boxes each with a copy of emulator x studio) and going to get a dual g5 to run reaktor in standalone mode through my motu 2408 all going to my soundcraft ghost 24 channel console and being tracked into my RADAR. going to get a kurzweil ksp8 8 channel effects unit to use on the ghosts 8 bus.
it will be nice to mix 16 tracks of 192khz samples on the ghost and track them to RADAR.