I just did a search and found this...
Apparently the IRF4905 is popular among the RC community for speed controllers...
http://www.oatleyelectronics.com/kits/k161B.html
Anyway, all the big suppliers I know (DigiKey, Mouser, MCM/Newark) are out of them at the moment, so we are basically waiting for International Rectifier to make some more. Newark actually has some, but they are the wrong package type, (we want TO220AB) so they won't work.