For your second airplane, it will be hard to beat a 4-Star 60 with a .61. A buddy of mine had one with the TT .61GP in it and it flew great. It did all the acro except 3D and it landed about like a trainer.

With a .61 it won't have sustained vertical, but it will be fine for a second plane. After you get used to a low wing plane and if you do want more power, you can replace the engine with a .91 like the Magnum .91XLS, OS .91FX or a .91 4-stroke.