I have seen good things from the Evolution trainer engine as another option for you.
http://www.horizonhobby.com/Products...ProdID=EVOE100
I really like the TT Pro but if you can't afford the extra, you can't afford the extra.
A guy at my club went to a swap meet and someone was selling the TT Pro46's for $50 each, brand new. I wish I had been there.
PS: do you already have the OS 46 LA? why not use that?