Oh god, been so out of it. Anyway, Yes I am positive that it is the GFX card fan. The rattling stops if I slow the culprit fan during rattling and starts making noise as soon as I let it run.
I have heard that this is a fan bearing issue and I recall coming across some posts on different forums suggesting it's a known issue. RMA'ing isn't an option for me, so I am looking into accessing a replacement fan with the same voltage specs, CFM. thickness, radius to replace the one on the car in case it ever does fail. Or maybe a cheap aftermarket cooler.
I have seen some Evercool fans on Newegg that may be an option, but I think I need to do more digging.