I want to run a rc of windows 7 but still keep my xp as it is. is there a way to do that like run it on sun virtual box and choose to run it at start up (i dont have hardware virtualisation)

Hi.
I want to do some virtualization using either Sun’s Virtualbox or Vmware. I will use Ubuntu as host operating system and I want to run about 8 installs of XP concurrently as guests. All of these XP guests will simultaneously do stuff on the web.

I need to buy a monster machine to handle this. My money can either buy me an i7 cpu with a little DDR3 ram (4-8gb) or a Quad Core (q9400) with about 16 gb of DDR2 ram.

It seems like the cpu is powerful enough in both cases, but I believe the extra 8gb or ram will come in real handy when it comes to virtualization. I believe the bottlenecks in virtualization would be located elsewhere, such as I/O. Please tell me what you feel would be my best choice.
4 answers in about 10 minutes… wow ! Are you guys on standby waiting for these questions ? Anyways, thanks for the good answers so far. I will wait a while until I award the winner to see if some more geeks respond. Please keep ‘em coming people.
I respect the opinion that the i7 is the fastest cpu and is good with virtualization, but I think i will go with quad core, cause I believe I need as much extra ram as my budget will buy. Honorary prices to all that suggested that Quad Core is the way to go, Quad Core is what I will choose. I will vote for user "Divot" as the winner though, because of his valued opinions about cache and DDR3. Thank you all that responded.

ok, my desktop runs xp pro. its graphics card has to dual vga out. if i put another monitor, additional mouse and keyboard (both usb), can i run virtual, sort of 2 pcs that can play games on lan? if this is possible, how to do this, what software to use?
thanks,
sun