OK, first to Mody, if your radio doesn't have a removeable module in the back your out of luck. I have an old Futaba 9-C radio and the Hitec module just pops in the back. Jr sells the module also and you can get them for JR and Futaba then be able to use there type of RX. hsukaria, the most force generated on our RC planes are the rudder and elevator so I always install my best servos there. The ailerons don't require all that much force so my lesser servos go there. I have often used the HS 81 or 55 on throttle depending on the room in the plane. I have some pretty big planes {sometimes} and I like a standard ball bearing servo with a high speed on the throttle just for the smoothness and speed. This is just a general statement from me, others do different things but a lot depends on the plane itself. Most of mine land in the IMAC or Pattern types. 3-D is a total different story. I don't/can't fly 3-D other then a hover or two so I'm not the best one to answer this. 3-D planes have such large surfaces and they are under constant movement they require the high end digital servos, both speed and power. I have some big servos in my 30% Extra and all digital. My friends with 40%+ planes have some huge servos compared to mine. Buy the best gear you can afford and you won't be disapointed and it will be with you for a long time. Mine sure has. If you can't afford it then get the gear that will work with the plane you have and as you move along in the hobby you can upgrade. The old gear will still get used, don't worry too much about it.