RE: want a brushless buggy
I would go with the Caster too. Get the RTR if you want to get into brushless the easy way without trying to find out what works, fits etc. No conversion kit needed and handles better than most other brushless buggies due to the twing batteries in the rear which makes the weight about the same on both sides. Other conversions tend to tip to the side badly on larger jumps because of the big single battery on one side. The Fusion stays nice and level and helps out in handling similar from side to side.
I run the Fusion Race roller with a Medusa Afterburner 200kv motor with a Mamba Monster Esc. Works great for me. I run the roller because the RTR was not out at the time or would have gotten that instead.