What controller for 8S that has a true brake??

[BrianG]

The only thing I would add is that if you go with a HV setup, pick an ESC that will handle at least 2s more than you plan to run. The back-EMF from the motor braking at high voltage can get quite high and may exceed the FET and/or capacitor ratings. And if you plan to use lipos, be aware that these higher-voltage pulses could negatively affect them, but have no actual comparison data to support this - just common sense.