Which older generation HP Proliant or Dell PowerEdge Servers support virtualization?

Hello,

I am trying to create my own learning environment at home. I tried to start with Dell PowerEdge 2850 and HP ProLiant DL380 G4 only to find that neither one would support virtual machines.

I've been trying to find which servers might support virtual machines.

Can someone point me to one of these ProLiant or PowerEdge servers that would support virtual machines? I'd like to find a modestly equipped server that won't break the bank that I can learn with.

Thanks in advance.