I have a 6 channel radio right now and I've been wishing I'd have gone bigger. You wont need a lot of seperate channels, in my case I need to mix a couple of channels. I have two aircraft with 4 servo wings and one has retracts on top of that. It would be easier if I didn't have to mess with y-harnesses and in line servo reversers. I could be wrong, but 9 channels would probably do everything you ever needed. Like it's been said, depends on how deep you get into the hobby.