Inherited HD3 PCIx cards and want to run on PC

[albee1952]

What mobo and cpu can I use with these cards? Assuming Windows 7 as I have a license for PT 10HD(which I already own). I saw the thread above, but the most recent post is from 2012, so looking for more current recommendations. Guessing I can find older mobo and cpu on ebay. My alternative is an old G5 Mac, but that stalls me at PT 7.4HD(which I don't own), even though the cards will fit(cards are currently in a G5 that will not boot). Already have a Glyph firewire drive enclosure and 192's. Just trying to piece together a working system on a tight budget(already have case, PSU, graphics and drives). Just need a mobo that is compatible and can host the PCIx cards.