Anyone with a 2012model comment on the wifi reception. I'll be about 40-50 feet from the router through a couple of interior walls and it will be low to the floor under desk. I was thinking of getting a PCIe wifi card in case the internal one is pretty low quality
All good for me, I'm about 30 Metres away from my router. You need to figure in which band you're on, channel of WiFi and other external factors.
The Mac Pro itself is a faraday cage in effect, bluetooth is a known issue for many, simply google Magic Mouse stutter and you'll see the result is poor design.
I had a Quad 2012 that had struggling bluetooth and that's with the Magic Mouse right by it on the desk! Apple swapped it out and I paid for a 6 core luckily no issues here but my guess is the class of bluetooth in the machines differs from build to build.
Anyway I have gone on, cool story bro - in short you should be fine.