Sounds like what you are needing is similar to a remote control for model aircraft, or model cars, boats etc. Normal RF transmitters will only have voice capability, and to control servers remotely will have to have a transmitter that will generate separate frequencies or sub tones..however the remote controls work.. I have built and repaired many radio transmitters/recievers..but never got involved with remote control items.
Maybe you can find something at the following hobby site:
http://www.pcwebdo.com/remote_control_aircraft.htm