DVB-C Card on 771 Mainboard?

Hi there.
I'm planning my setup right now, and I'm not really sure what to buy. LinuxMCE is one part of my project, but it doesnt end there, that's why I will setup it in xen (under fedora werewolf)
Now I do have a problem. Since I need a lot of performance for a few of my projects, I'm going to go to the 771 standard, and buy a quadcore 2,4 ghz processor.
But most of the 771 mainboards don't really have too many PCI Slots, so I have a problem getting dvb-c cards in. so my question is.. would you use another computer, just for the TV part ? And what would I need for that one? Performance-wise.
Another solution would be USB interfaces for the cable.

So in conclusion:
1. Would you use a own computer to build the TV interface in my home.
2. Can anyone recommend DVB-C Cards ? USB or PCI ? I'd like to have 4 possible streams, so I guess twin tuners would be great (I think that's how they're called)

Alright.. that's it for now. Thanks in advance.