From the information you've given us, we can only recommend one thing...

Get the fastest processor you can afford.

I would suggest going to the forum for the recording software you plan to use and see what kinds of success / problems people are having with each.

HI,
it depends on the software.

generally, if high track count (or high res) with lots of effects then quad.

if lots of samples then fastest FSB and Ghz. most samples are not quad able

Scott
ADK

thanks ill check the other place. i think im using cubase sx3 for now at least but definetly on the cubase line
thanks