You know I may have this wroing. Does prebuilt mean take it out of the box and fly, or is an almost ready to fly that needs 4-10 hours of assembly fit into his idea of already built? He would have to buy a radio and receiver, servos and a speed control and install the electronics in the plane. Then he would have to balance the plane.

Would that fit his idea of ready built?

For example, the Great Planes Spectra, that I mentioned above, is available as an ARF or an RTF.
http://www.greatplanes.com/airplanes/gpma1050.html

The ARF probably would take 4-8 hours to get ready for flight and you need to buy the electroncis yourself.

The RTF comes with the radio and all the electronics installed. Fly in an hour or less.

Which is your Uncle looking for?