I figure something like that as well
maybe one can add some additional fans simply. If I look at 7950s with 2 or 3 fans, the casing is pretty open.
water-cooling is a no-brainer, price aside...
Yes, I was able to improve cooling tremendously by just placing a couple 120mm fans blowing directly onto my GPU's. There was so much heat generated by the GPUS, there was in issue obtaining "cooler" air from the room into the case.