RE: 4CH VS 6CH?
I just got my first plane. I got the Nexstar ARF. ARF allowed me to choose my radio and engine, in case I wanted to upgrade or save a few bucks. It also gave me the opportunity to assemble the plane to see how things work, especially in case something needs to get fixed down the road (which it will).
I chose a 6 channel computer radio (Futaba 6EX). The Nexstar has instructions for adding extra aileron servo, and with a computer radio you can enable flaps. While they are not needed on a trainer, it will give me the opportunity to experiment with some options and modifications, and thus enable me to get a more advanced second plane.
The Nexstar ARF does not come with the AFS which everyone says to turn off anyway. It is one of the easier planes to assemble, looks great too, and parts are available everywhere. There are some who might say negative things about this plane, but they are outweighed by the thousands who have trained on Nexstars and loved it. One guy on one of these posts somewhere even made some awesome modifications and turned it into a tail dragger, and removed the dihedral for a sportier flying plane...it looks great.
Anyway, just want to plug the ARF planes over the RTF planes. You will learn and gain a lot from the experience of assembling your plane.