My 2 Cents:
If you're serious, look up a slaughterhouse or a butcher near you and ask for blood. They'll sell you pigs blood fairly easily.
I'm not sure how you'd keep it from coagulating, though. My best guess would be a bunch of ground up aspirin mixed into the solution.
I'm betting the blood will be conductive, though. It is iron-based after all.
Blood may do a nice job of moving heat in our bodies... but a WC loop and our circulatory systems are not the same
Anyone who wants to use blue blood will be disappointed the minute it's exposed to oxygen...
As for pumping, I'm not sure how you'd do that. I would think the aspirin would make the blood a little less viscous, but I bet you could go over to the WC section and ask for the strongest pump practical for use.
I'd recommend some cheap parts for testing, I don't know why everyone is so creeped out; blood isn't satanic or anything of the sort... I think those who eat meat would be surprised at what goes on at a slaughterhouse if they're so creeped out about blood. Hell, the Mythbusters do enough tests with pig's blood.