I like carrellh's recommendations for pairing with the Tower Trainer 40 MkII ARF. The Laser 4 radio system is a really good value - it has a metal handle, offers v-tail and elevon mixing, and comes bundled with ball bearing servos. It will buddy box with other Hitec or most Futaba radios for training purposes.

The Tower Trainer .40 MkII actually ends up pretty nose heavy with a ball bearing .46 on the front of it. The RTF comes out of the box quite nose heavy and the manual recommends adding weight to the tail once you check your CG and discover this.

The Thunder Tiger Pro .46 is a fantastic engine in every respect. I'm not trying to talk you out of the TT Pro .46, but you could save $30 by ordering the Thunder Tiger GP-42 instead. The plane will balance better and the GP-42 will still provide plenty of power to fly the Tower Trainer 40 MkII with authority. Folks will tell you not to buy a plain bearing engine like the GP-42 because they're weak on power. They are actually thinking of the O.S. 40 LA and .46 LA. Nobody who's ever flown a Thunder Tiger GP-42 or GP-61 would ever claim they were weak on power.

The Tower Trainer .40 MkII would also fly well and balance easily with a ball bearing .34~.36 2-stroke like the Super Tigre G-34, the Thunder Tiger Pro .36, the Evolution .36NT, or the O.S. Max .35 AX. You'd simply want to order a 10x5 prop instead of an 11x5.

The Thunder Tiger, Super Tigre, and O.S. Max engines normally come with a glow plug. You will need to order some medium fuel tubing in order to finish assembling your ARF.

Good luck and good shopping!