Haven't worked on this for a while, but I did make progress on the motors.  At first I just hollowed 2x4 lego bricks and fit a small motor inside.  I invested in a 3d printer and after learning that somewhat, I was able to start making these (Pic below)  Next I am going to work on a casing for the electronics that would also work with legos.  So far, I haven't had much luck with due to warping and shrinkage.  After the part is printed, the fit isn't quite right.  I had better luck with the smaller motor blocks after I adjusted some settings and made a few small modifications to the size of the pegs.  Since this is one of my next projects, Im hoping to have it done soon.