I am well aware that having heatpipes alone can provide good cooling on it's own. What I, and a lot of SFF owners don't want is that heat radiating back into an already cramped case, which is why they're modding the NV Silencer 5 or using the NV Silencer 6 with the 7900GTs. 120mm fan isn't an option in this instance. Combine heatpipes with a good fan and external venting capabilities (i.e. the 7900GTX fan), and that goes a long way to keeping your card cool as well as helping to vent your case.
Artctic Cooling needs to get around to realizing their customers want an NV Silencer for the 7900s. In the interim, if anyone finds out who sells/makes the 7900GTX coolers, I'd snap one up in a second.