^^^ seconded. The GTS512 has a dual-slot cooling fan. Cools better than then single-slot crap on 8800gt & 9600gt. & runs quieter. You don't have to get factory-overclocked cards. You can do it yourself with rivatuner.
You can get 2 BFG 8800 GTS 512 OC (clocked at 675) cards with a lifetime warranty for around $200 each. I can overclock mine additionally another 100Mhz to 775, without any problems what-so-ever. Could probably go higher, but it cuts through everything I do like a hot knife through butter, so I'll just leave it there.
If you live by a Frys, they have them on sale right now for $199, after a $50 rebate. Retail!
The Akimbo cards come with a dual slot cooler, so thats a non-factor. The performance differance between the GT and GTS is pretty negligable, so unless you can find GTS's well priced, Id say get the superclocked GT's