David,
It seems to me that if you had air brakes now in use it's better to stick with those really. Like Carsten wrote the electric brakes are not long lasting (I have heard also other similar cases). Due to very poor 2S braking force I'm actually in progress to try 3S separately for brakes only (as gear mechanisms won't tolerate 3S). And on bench tests even 3S is not too much better. You could use gyro steering for nose gear still.
BR, Ilkka