Just to expand on a few points:
120G Vertex2 3.5in is good value
as are some of the intel range.
Have had issues with some GTX285 re-flashed (not all) - just beware...
There is a UK source of these...
Nvidia Quadro4000 prices have dropped recently too - I think they are worth the money
I wouldn't pay the price for a PNY's Quadro FX4800 for Mac though! especially if apple manage to fix the ATI problem
You may also want to invest in a couple of DVI Parrots to manage the EDID/HDCP if running 10.6.x and above...
S