hang on a minute - is that an SLI connector in the top left of the first picture?

Two of these babies in tandem? Lawks a mussy!

As to the cooling, this thing looks to be around 15" long, perhaps more. Some reasonable vapour chamber technology and a large fin array - perhaps extending beyond the area of the PCB or wrapping round to the back of the card - would do the job. Although watercooling would definitely be a better way to go - inclusive closed-loop all-in-one kit, anyone?