I am looking to develop my knowledge of virtualisation systems and server management and I am not enjoying running all my lab stuff through a hypervisor on my main machine as it restricts it's use for other things when I want to keep 5-6 VM's constantly running. So I have decided on some dedicated hardware, but my knowledge of server kit is limited at best. I am basically after something I can stick ESXi or something on and run 3-4 server and 2-3 client guest OS's on. I am not after stunning performance, but I do want to run it as a quasi live system running a local domain with 2-3 physical machines and a NAS box. I am guessing Xeon for the better handling of virtual environments (dual Xeon for pimp factor?) and 16gb RAM minumim? Ideally it has to be tower system as I have literally no where to stick a rack. So what would be capable of running this and how much is it going to damage my wallet?