Stealth Pyros said:
I've been hunting endlessly for one for months as well, and still haven't found it. Not even eBay has any listed!
I never found a fan-cooling alternative and ended up liquid cooling my whole PC--more as a fun project than for any cost-justified reasons.
Swiftech still sell a liquid cooling system for the 4870x2, if you're curious. Of course, if you go down that route it'll set you back a few hundred bucks for the whole system and likely require modifying or replacing your case.
On the plus side, you'll be one of the coolest nerds you know