I have been impressed with the Zotac cards which use custom cooling from Zalman.
With that said, you are lucky to be able to purchase a card from Gainward, which are not available in the U.S. Gainward really seems to be creative and cutting edge on most of their graphics card designs. For example, I see that they make a 2GB version of the GTX 460 with Gainward-designed custom cooling. That is a pretty rare configuration, and the thought of getting that in SLI makes me drool. They also use high quality components and offer the "Golden Sample" cards, which are specifically tested to overclock above and beyond regular cards. I have owned a Gainward card in the past (Bliss 7800GS+, one of the only AGP cards that used a 7900GT chip) and wish we could buy them in the US.