[Batfish]

You should also consider the Novak GTB systems (4.5, 5.5, 6.5) for your truck, since you said you'll be running 6 cells.
The Novak systems are a great drop-in option and offer a very good performance. The only downside when comparing the Novak system to the sensorless systems (MGM/BK/MTronics) is that the Novak is not as expandable. Specifically, you can't run higher cell counts for nimh or run more than 2s lipo with the Novak, but you can run the higher counts with other controllers.
One benefit to the Novak is smaller size, which definitely helps when mounting in a stock vehicle. There's no way I could mount an MGM or BK controller in the 4wd buggies I run.

I have the Novak 5.5, which I have run in 4wd 10th scale buggies and 2wd 10th scale stadium trucks, both on 6-cell nimh and 2s lipo. The Novak 5.5 setup is too fast for the track - I have to tune it down with my radio to be able to control the vehicles.