1) Don't get a Prescott. They still run rediculously hot and require large ammounts of power, for little extra gain in performance. Get a dual core instead (and possibly switch to AMD).
2) The Prescott 6xx do have 64-bit extensions (SSE3 ?) but are not true 64-bit processors (they are still x86 architechture) so they won't need an x64 OS (in fact they won't even run on one). You'll have to get a regular WindowsXP for it.
3) As for cooling, don't use Intels stock fan - it's useless. Get the in-a-box version for the extra warranty (if you want it), and then slap a high-end Zalman heatsink on it. In my own case this almost eliminated fan noise, and the CPU temp dropped from 60 to 37 degrees C.
In short, I'd go to a site like Falcon Northwest or Alienware and look at their top models for inspiration. Then try and build something similar.
2) The Prescott 6xx do have 64-bit extensions (SSE3 ?) but are not true 64-bit processors (they are still x86 architechture) so they won't need an x64 OS (in fact they won't even run on one). You'll have to get a regular WindowsXP for it.
3) As for cooling, don't use Intels stock fan - it's useless. Get the in-a-box version for the extra warranty (if you want it), and then slap a high-end Zalman heatsink on it. In my own case this almost eliminated fan noise, and the CPU temp dropped from 60 to 37 degrees C.
In short, I'd go to a site like Falcon Northwest or Alienware and look at their top models for inspiration. Then try and build something similar.