适用于开发人员的VMware或Hyper-V

I'm looking to replace a couple of machines in the office with a more powerful multi-processor machine running either VMware or Microsoft's Hyper-V with a view to hosting a mix of Windows Server 2003, Windows Server 2008 and Linux operating systems. The machines are used mainly for testing ASP.Net or Perl web sites. I don't need advanced features like live migration of running systems but it would be useful to be able to restore a machine to a known state. Performance is not really a big issue either unless one is noticeable faster than the other.I'm looking to replace a couple of machines in