Need advice on parts for a [special] machine

Hey guys,

I'm just looking for some input on a few possibilities for a Hyperconvergence machine of sorts. I'd be using it to try some unraid stuff, VM's, and Windows server functions. You know, something relatively beefy to do stuff that I might not want to do to my main machine.

So I've got two machines that are currently in running order that I could do this to. One has a Xeon e5430 with 8GB of RAM in it on an Intel S5000PSL board, along with a total of six gigabit ethernet ports. The other machine is an older Dell Precision, which has an Intel Core 2 Quad Q9550 with 16GB of RAM in it.

I've also got an iffy i5 3570k machine, which seems to run fine for a couple days after a fresh install, but starts to BSOD like mad after about a week. (if anybody has some clues as to how to fix that, I'd be eternally thankful)

I'd just like some input on what machine would be the best suited for this, and what upgrades I should consider for them.

I've got the graphics deal all sorted out, I've got a set of 2 260x's and a bunch of cheap Quadro and NVS cards.