i personally use a dual quad core xeon and swear by it, i have a similar home server for a (using the technical terms) "Bricks" business, they offer good performance if you dont bogg the processor down, and with cPanel accelerated the performance is great.

pricing often isent to bad although now i7 servers are comming avalible as the prices come down as will dual quad cores as they are replaced...

it will be interesting to see if the i7 or the dual quad will be cheaper or similar soon, one can only hope hey?