Hi Creeky. Welcome to the froums.

I recommend going for the quad core over the dual core because they're not much more expensive and once you get started, you may well find you'd prefer to be on one PC after all.

I started with one WoW on my desktop and four on my laptop with keyclone taking care of the hard stuff. Within two weeks, I wished I was able to run all five on my desktop so I could PiP between them. I'm in the process of building a new PC just for this reason (Q6600, 4GB RAM, 8800GTS). Initially, I'll be on one 1680x1050 display but we all know how long that state of affairs is going to last (until payday).