I run Photoshop CS on a home built PC.....XP2400, 512Mb ram, ATi Radeon 9600 and 120G hard drive. I have the Watcom Graphire 3, a 19" LCD display and this works fine for me. I run on W2K and have a Canon i850 printer.
Colour Management is a hot topic. It depends on your screen, CRT or LCD. Most people think CRT is better and certainly most of the Gamma Correction S/W is geared towards CRTs but you can calibrate an LCD with a bit of twiddling. You don't necessarily need h/w to do this...which is expensive.
You can check out the Photoshop Users Forum at Adobe and get lots of help there.
You'll find lots of postings on Colour Management there.
Have fun