[all variants] Virtualization Server?

I've started to research a new project i'm looking into for use at my home. I've had a rough start to finding information I was hoping some here could help me or at least point me in a direction.

I was wanting to take a gaming pc I have and run copies 3 copies of virtual machines. I'm already doing this with Virtualbox.
i.e.
Opensuse
WinXp
Fedora 18 Alpha.

What i was hoping to do is find some software where i could use two pent 4 pc's i have to setp virtual machines so that when they boot up instead of loading their normal winxp i could have them load a copy and/or one of my virtual machines on my gaming pc.

some notes

both intended pc's are Pent 4 with 2 gigs of ram and 150+ network cards. My wireless network only has 3 devices on it and all are 150n compliant or higher.

My gaming pc is:
Quad Core amd
4 gigs of ram
Ethernet 100Mb connection.

Any ideas how i could make virtual machines on my gaming pc and have these 2 pent 4's boot my virtal pc so that the load of what they do is on my gaming pc instead of the pent 4's?

Sort of like a server virtual macine & 2 workstations setup.

Thanks ahead of time!