Save your flight sim money and download the free flight sim called FMS. Ya its not real fancy but it works well and lots of FMS fans have created different planes that you can download as well. I have been instructor for the past 4 seasons. Once the trainers are in the air, there rreally isn't a "big" difference between them. The Tower trainer will work fine and nothing wrong with a 4 channel radio. I still have mine along with a newer 6 channel. The extra 2 channels are usually used for flaps and retrracts. Our field eats retracts for breakfast so the only use for the extra channel is flaps. Planes that need flaps are usually bigger, heavier, faster planes that you won't to be trying to fly for a few seasons any way![