Everyone will have different opinions about the motor to put on. Everyone will say to invest in a 46AX. Which is a fine motor, but to get a plane in the air such as the tower trainer, the os46LA will have more than enough power.

I ran an 46LA for over a year on a trainer, then a TWIST (Kind of underpowered) and a mid wing plane, it pulled great. If they are broken in well, the 46LA has enough power to do more than most people think the little engine is capable of. Plus, you can't beat the price.