Looks like water cooling is the way to go. Expecting the cards and chassis to come in somewhere next week. Got a very detailed e-mail from EK with their products which also mention the full cover 7990's so will look into that and puzzle it together so the cards, chassis and hopefully the water cooling products arrive at the same time.

Also did put in a secondary PSU to make sure I do not run into power issues when the four 7990's are running at max speed.

Regarding the liquids to use, i see they have copper and nickel plates, any advice there what to use in combination with what liquid?