The MSI TwinFrozer is okay.
I think I'd vote for the Asus DirectCU II version of the GTX670. http://www.techpowerup.com/reviews/ASUS/GeForce_GTX_670_Direct_Cu_II/
It makes absolutely no sense to add your own cooler when it's cheaper to get this card which would do it better (it's not just the cooler, it's also the better power circuitry). Plus, you'd VOID YOUR WARRANTY.
IMO after-market coolers for graphics cards will likely disappear since so many companies have started to do it better for cheaper.