Nope,it won't be enoguh.
If you want to buy an aftermarket cooler for GPUs,buy ACCELERO 8800 EXTREME,or a full PCB cover GPU block from Zalman,and install it on your GPU/s.
http://www.youtube.com/watch?v=u5PtiwUQMk0
See this video,you'll see what am I talknig about...You could use it on 7900 where only GPU is hot,but on 8800,you need to cool down mofsets and all other components on the card to avoid crashes

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EDIT:Zakaj pricamo na engleskom kad si iz Osijeka

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