You can always get this motherboard (if you can find one):
JetWay JNAF93-Q77 LGA 1155 Intel Q77
It has 4 PCI slots and runs HD 8.1 fine under Win 7 64 bit. Mine has an i5 and 16 Gb of RAM. A license for HD 8 is $50 on eBay. Get some 192 interfaces cheap and have at it. I clock mine from a Antelope Zen Studio plus with the mic pres out into the 192 or Omni via ADAT. I'm also looking to get another couple of 192 Digitals for feeding from separate VI computers. I've got 24-28 mic pres into mine (depends on sample rate 28 @ 44.1/48 KHz and 24 @ 88.2/96 KHz). I mix with my "Vanilla" PT listed below. All kinds of fun can be had with these things if you go in with an open mind. Have phun!