I have an i7-960 that I consider basically useless. I was using it as a GPU feeder before, but it always ran so hot, with 3 different coolers it never did run under TDP (even without a case) - it needs liquid. I fired it back up for the last WOW Event and it ran 5125 RAC under linux CPU only. Nothing to scream at. It now has 2x 1050Ti @ 46k RAC running 2 CPU cores - and still screaming hot.

I did a comparison on CPUBOSS and the GeekBench results say the 960 is 15.76% better than the 860, so that would put it around 4430 RAC to expect. Being a rack mount unit (you did specifically say that, but I assume) it will be LOUD. And I'm not sure what to one would expect for PCIe slots to use, and cooling for them.

I think 70 is about $120 CAD, that would be about all it is worth. To me to noise would be unbearable. But the rack I would use, LOL.

For around $100 CAD I can get a used 750Ti and expect about 16k RAC or $200CAD for a new 1050Ti for 20k RAC. Drop a single card into one of your other computers (you have Linux too) and get much more performance for a similar price and a LOT less power use.

My 2 cents, Do you need a rack, that may be your deciding choice ...