You'll just wind up like me gaara and yearning for even more power
It is a good deal for $100, but man the 6800GT is awesome, that's why I upgraded
Also I wouldn't worry about the chipset dude, it doesn't get hot like the socket A systems did when adding voltage and chances are you might not even have to add voltage. Check out some more of the peoples high *** OC's at xtremesys and you'll see they don't play around with the chipset voltage very much, and due to the position of that heatsink it's basically impossible to put on a good after market heatsink because of size reasons. The one there is already good.
Also concerning heatsinks, the only ones that have a tendency to create negative effects is the RAM heatspreaders in some instances....although these new heatsinks are huge they are infact effective, otherwise they wouldn't be so widely used as awesome air cooling solutions......zalman is an exception because relative to the amount of copper it's pretty small, it's just really wide.
When it comes to mosfets though the heatsinks absolutely work 100%, no negative impact at all as those damn things can get HOT as hell.....I'd suggest either some AS5 in the middle with super glue on the sides like I did with my teakmonters or thermal epoxy...because thermal tape kills performance.