My understanding is that the torsen diffs won't hold up to brushless power...never tried it so I can't say from experience.
I personally like the Ofna Hyper 8.5 or Jammin CRT Diffs (the 8.5 diffs have a really good seal-my experience). Another reason I like Ofna is because its always easy to buy diffs on ebay dirt cheap. The Lightning diffs are good too...I have them in one of my trucks-no problems.
Mike sells a kit for $125...but you need two kits per truck, which equals $250.
If you don't have the Mike FLM diff case, you can't put any other diffs than stock in the revo.
You absolutly need the RCM hybrid diff case, and you can buy the "case only" option, and put the diff you want in it.
Personaly, i love the Kyosho diffs, that's bulletproof.