OK, in my opinion, and I know the opinion of several others here you can't get a better trainer than the Sig LT-40. It comes in either kit or ARF (Almost Ready to Fly). I've had one for 13 years now, still flying (at least it will be flying after I fix it). It is almost a 60 size trainer so it is easy to see. It has great handling qualities for the beginner. It flies great with a .40 or .46 size engine. I first had an OS 40LA on it and it flew fine but after a while it was too small for me. The 40LA was a bushing motor (they don't make it anymore) and was low powered and disposable. I'm now using a Tower Hobbies .46ABC (more power, but they don't make it anymore either). I know the OS engines are reliable, just make sure you go with a bearing motor. I haven't used any other brands in 2-stroke. If you want to try a 4 stroke I know the OS engines are good, so are the Sato engines.

Welcome back and good luck!