Not sure what kind of a budget you're on but. For a low cost basic engine I would recommend the Thunder Tiger GP42. They are about $50. If you plan on being ion the hobby for a while, it sounds like you are I would go with a TT PRO46.
Quantum Models has them for $74.00. It is a great engine for the price and you can use it on your next plane when you are done with the trainer. We are using these on our planes and have had no problems. The Senior I am bringing down has a GP42 so you can see how it runs on Saturday as well as the PRO46's. The engines are very easy to tune and setup.
If you are planning on staying in the hobby for a while I would recommend a 6 channel radio setup. They will cost a little bit more than a 4 channel but they give you some additonal features such as dual rates that you can't get with a 4 channel. You won't really need all the features on a trainer but you will when you get your next plane. Once you figure out where you will be flying, I would suggest you see what is primarily being used there and go with the same brand only because it will be easier for someone else to help you if they are familiar with the radio you are using. My son and I both have Futaba 6xas since you can program up to 6 different planes on the same radio.
I'm sure Mike will chime in and give any other info I forgot. We can discuss indepth on Saturday.
See you then....