If you find an old chassis with the AC motor, you can steal the motor and mounting plate and add the second motor. With the addition of the AC Commander, it's a very nice package. I was very surprised how much better the low speed performance is with the 100 steps and probably the better logic of the AC Commander.
I've added some additional lighting to the front as well, blue lighting in the turbine vent and a red LED below the headlight. I also replaced the headlight with a white LED for a much brighter light. On the tail car, I added LED's to properly light up the rear lights.
