My vote is for the Bonneville HC too. I've got a pair of Delta's on one cooling a 7900 GTX and a pair of Opty's - OC'ed, of course. The Opty's are running ~17°C over ambient at SETI load. And there's no need to mess around with soldering this or that - my 1/2" tubing fits right over the 1/2" copper tubes coming out of the HC just as Mustanley's do. It's simple, easy, cheap, and efficient. The shroud is made out of 1/8" foam-board and 3M shipping tape, which can be painted if you prefer. Mounting is easy using cheap bolts from the hardware store ...