I have set up 2 airplanes with the quad flap/crow modes, but both used 7 channels, 4 of these are in the wings, one for each servo. With a 6-channel radio, you can do most of the stuff, but not get full span ailerons since both flaps would be on the same channel.

I checked the Ultra Stick manual and the 421EX manual and it appears you can have flaperons using the full span aileron set and a flaperon wing type with one aileron servo plugged into the aileron channel and the other into the gear channel or you can have separate flaps using the ailerons and flap set with the gear channel for the flaps.

If you use 4 servos, you would need 2 Y-connectors, one for your ailerons and one for flaps.