I bought my KT controllers from PSW power:-
www.pswpower.com
The waterproof Julet plug versions have a 3-pin plug for rear and brake lights. I have soldered them to aftermarket lights and they work well - the brake light works with the brake lever cut-outs and the rear light comes on when the display backlight is switched on. There is a useful wiring diagram with the listing. I'm unsure if the block connector versions also have a light function, but an email to PSW should confirm.
I have a 15A 6 mosfet powering my Yosepower 250w. motor and a 20A 6 mosfet with my Yosepower 350w. motor. Both run cool on max amps with PAS 5 on some quite steep and long hills. I'm very impressed with them.

KT kunteng Electric Bicycle Motor ebike Controller 24V 36V 48V 250W 500W 1000W Brushless DC Sine Wave sensor Controller
KT kunteng Electric Bicycle Motor ebike Controller 24V 36V 48V 250W 500W 1000W Brushless DC Sine Wave sensor Controller
I have a 15A 6 mosfet powering my Yosepower 250w. motor and a 20A 6 mosfet with my Yosepower 350w. motor. Both run cool on max amps with PAS 5 on some quite steep and long hills. I'm very impressed with them.