Here's my final setup. Thx to deuce, dunk, p3, and behemoth for the help.
My setup is built for complete silence as I hate having the buzzz of a Pc Tower.
I went for a Quad Core 2.83 Ghz processor and this works absolutely awesome with 3Gb RAM.
The video card is specific as it's one of the few that doesn't use fans for less noise. It's an NVIDIA GFORCE with a refrigerating system.
The Tower is an ANTEC SONATA (the absolute best - again for noise considerations)
The computer works absolutely fine with Vista, a dozen open prgms, multitabling on several sites, trackers and having skype convos...
Screens are 2x Acer 22'' and I now usually also have my laptop for emails and stuff.
I use the MX Revolution keyboard + mouse from Logitech and although I feared wireless stuff, I haven't had a single problem with it. Btw I strongly recommend the mouse. It's he best ever had.
I added Logitch webcam, speakers and Bass booster + a pretty good headset and also a 3G connection backup in case of loss of my normal one.
Gonna buy an Aeron Chair.