Adding powered trucks to dummy units is a great way to go, and have what you wish. I have done so with PW F3 units that have been repainted for certain roads. It would be easier to do so with modern can motors and putting in ERR electronics is never a problem. Having done so, to have two powered A units, and no tether necessary, is very simple and quite effective. With the "nudge" feature of ERR TMCC units, getting the two A units to run in synch is very easy to perform.
Jesse TCA 12-68275