Maybe I am missing something, but I am wondering why the question seems to be "flaps or landing gear" why not both? With a 6 channel radio, gear is usually assigned to channel 5 and flaps on channel 6. Assuming you're radio is at least 6 channels, a plane with flaps and gear could be accommodated. If you are using 2 channels for ailerons (1 & 6), use a "Y" harness for the ailerons, which would free up channel 6 for the flaps.

DaveB