Hello again all, thank you for your replies, it's very helpful!

However, it turns out that the request for me was stated incorrectly, 
they wanted a dual core system, and instead requested a "dual cpu" 
system. D'oh!

Anyway, the floodgates' open now, I would rather actually go with a core 
i5 or i7, but of course one thing is still the same, I need to have SL 
5x on it.

I've previously had the Asus P5Q and had to install the NIC driver 
manually, which is a pain in the butt to say the least.

Is there a hardware compatibility list for SL 5.4 out there somewhere? 
Any more suggestions on hardware?

Thanks again!
-Chris Tooley