Once you have a system, the next thing you should do is look at flight packs. Mini servos are wonderful for all kinds of things. Buy a couple receivers and a couple battery packs and a good field charger. Obviously you don't need to buy it all at once, but having extra flight packs means you don't have to move your radio back and forth between planes. Plus if you buy a variety of servos, the possibility that you'll have the "just right" servo for any given application increases.