I'd recommend no less than a 3s 900 mah. I have a TP 2S 480 mah and I don't use it. I'm going to build a small, light plane for indoor or absolutely no wind that I'll eventaully get to use it on. You can save an oz of weight by going with the Esskay motor from hobby-lobby.com. It is the best performance for your $25 (on sale through 3/15).

With a bigger battery, I'd recommend buying a couple of 9x4.3 GWS SF props.