if this is for a corporate enviroment you will need to look at the Xeon range of intel processors.
if its just as a small project / play around with Virtualization go with either an i5 or i7 sandy bridge setup.
I us a Dell R410 (dual quad core Xeon's with 24gb of ram. connected to an iSCSI SAN) to run around 6-7 virtual servers.
------------------------------2700K @ 4.5 | Maximus IV Extreme-Z | 16gb RipjawX DDR3 1866mhz | 2x 2GB 5870's | Eyefinity @ 5760*1080 | 2x WD Black 1TB Raid 0 | EK&XSPC Water Cooled | Thermaltake 1200w PSU | Thermaltake Tai-Chi Case
No liability accepted or warranty given for advice Reply to hugostiglitz
Make sure to get the non k version if you are just doing small virtualization. An i7-2600 would be a good choice. However if you are doing high end stuff for a company a xeon server may be a good choice.
------------------------------Nap time!-amdfangirl Reply to amuffin