Hello. I've been out of r/c for a long time and getting back in. I'm looking for a plane radio system (4 channel, 4 servo) and wanted to find out what are some of the features that I should look for and what are some of the recommendations you guys can give me. I'm on a very strict budget so those $300 and up radios are out of the question. Should the radio be AM or FM, etc, etc, etc? Thanks