Matek F765-WING is the most powerful (probably) flight controller on the market. OK, technicaly it's not on the market yet since I only have one of the preproduction samples, but it is a powerful design.
Matek F765-WING will be compatible with INAV, Betaflight and Ardupilot. It is based on STM32F765 MCU, has 8 UARTs, 12 PWM outputs, I2C and 6 ADC channels for Vbat, Current, RSSI, AirSpeed. On top of that it holds a 8A BEC that can power all the servos you will ever have on your RC airplane model.