Just remember; you may only need a kit to fit a BB in a Revo, but you'll need a bit more to "run" a BB in a Revo. The Traxxas rigs are 1/10 scale and are built like 1/10 scale, you'll have to start building them to handle the power of a BB. If you grab a Savage or LST, they're already built to handle the power and are pretty solid out of the box.
Traxxas: Tons of aftermarket support, but they need it to be really good bashers (especially when stuffing a big engine in it)
Savage: Decent aftermarket support, good bashers out of the box, but they aren't known for their handling.
LST: Decent bashers, good handling, but the aftermarket support is lacking (may start coming back because of the XXL2)