I will have to go with the LST as well, or if you are trying to save money the Aftershock. The drive train is about as bullet proof as I have found and if you do manage to strip a diff out you can rebuild with the ti-nitride parts. Link I think has these in his LST, but he will have to chime in on that.

For cost and simplicity you could go used on an Aftershock or LST roller, I have heard of people getting the XXL roller chassis for as little as 150.00 USD. Then get "The Dude: racing mount for the motor and if funds permit the single speed conversion, though I have seen people make homemade versions.

If you go the Aftershock route, keep in mind here that the A-arms are not as stout as on the LST, but you can upgrade to the LST arms, hubs and drives easy. But there again you are talking more money. I personally have not had any trouble out of my Aftershock arms, but I am kind of easy on stuff. (I like to build about as much as anything) RPM also makes replacement arms for the LST/Aftershock.

Good luck let us know how it turns out.