LT-40
My trainer was a SIG LT 40, Thunder Tiger .46 Pro, and she flies great. A smooth forgiving trainer, that floats in like a butterfly. I still enjoy breaking it out and doing some slow relaxing flying with it. I have let at least 5 people who have never flown try flying it, and they all love it. All the planes mentioned are good trainers, but I personally like the SIG LT-40. A OS 46 FX would also be a great motor, and could be used on your next plane also!