JR is unique in that the buddy box needs to have a charged battery pack as well as the transmitter whihc is a pain as it adds another battery that needs to be charged. Other top brands such as Futaba and Airtronics don't require the buddy box to have a battery pack. As far as I know only a JR buddy box or transmitter will work with another JR tranmitter. The best trainers are 40 size and have at least a 60" wing span. One of the best trainers around is the Sig LT40. You can buy it as a kit or an ARF (almost ready to fly). It has a 70" wing span which means it can land nice and slow and is easy to see what the plane is doing. A Hobbico Avistar is an advanced trainer that has a sturdy build and would be ok with a good instructor teaching you. Midwest makes a nice trainer called an Aero-star. Any of these will work as they all have a high wing with a flat bottom. Check out the Tower Hobbies site to see what the trainers look like. Get an instructer at a flying club to help you or the plane and your time in this new hobby will be short lived. Phone the closest hobby shop and ask them where the RC clubs are. It will save you to belong to a club, not cost you!![8D]