[jitter] best Max / Jitter / Windows / PC desktop setup?

Hi, 
I've always been a mac user - but because of playback issues with Jitter & my MBP 17"-  I was thinking maybe the grass is greener on the "other side"? ...I'm thinking - buy a PC and customize for realtime video playback? 
(like a nice high-end 768mb video card & RAID) 


Has anyone else taken this route?
Maybe Quicktime and Jitter are happier in PC land? smoother - better frame rates? or not?


I was hoping someone could point me in the right direction as to which version of Windows (jeez so many) would be best for a Max/Jitter set up. My main patch is a polyphonic video 'instrument' (or mixer) which can play up to 5 or 6 SD (640 480 JPEG)  video streams, smoothly  - video output will go to a separate machine for recording. (mac / FCP )

any pointers / comparisons, experiences etc would be greatly appreciated!

thanks!
- jt