Wiki is a pretty decent place for a good read at least: https://en.wikipedia.org/wiki/Brushl...electric_motor
Brushless can be run on NIMH btw, but most brushless motors are high current and meant for racing/power and your battery needs to be able to deliver that current. Brushless motors are great but sourcing them in our 28mm size with the correct KV rating is kinda expensive and difficult. It is however GREAT for torque if you get a sensored brushless motor though the cost is much higher for these plus they need a special brushless sensored ESC. I've found around 800-1200kv at 2 cell lipo is AROUND scale speed or at least enough to enjoy without feeling like a hot rod.
Most all aftermarket motherboards can run brushless even if they do not directly support it, just run a Y-Cable from the RX to your ESC and your MB and just dont connect the output of the motor on the MB and you will get both sound and motor control. I have found lately that you get much more precise control out of a good ESC than just changing over to brushless IMO. LMK if you got any more questions!