interesting...
An indoor scale harrier would be darn near impossible to pull off. Horizontal flight would be doable, but VTOL and hovering would be iffy. One way to go would be to make the exaust ports wide open and uncontrollable cept for a micro servo controlling the thrust vector plus a helo gyro keeping you level. Another idea would be to use a micro servo controlling thust vector and a set of two micro servos or a set of coil actuators (if they have enough torgue for it) powering valves ducting the exaust, controlled by a set of simple gravity switches (the ones with the ball bearings in them) one aligned on the pitch axis and one aligned on the roll axis you would have to figure out a way to switch this method off after your transistion from vtol to flight else your inputs from your transmitter would be counteracted by this type of system. However all this stuff is adding alot of weight. For motors I would suggest dual GWS-EDF-50's one for each side. That is of course the plane is scaled to use that motor. You forgot to mention scale. I would also recommend very very light building materials. and scale up the wings just a bit to increase lift.
Just some ideas.