I just installed a ''WAYPOINT PRECISION SUB-MICRO 9.2 G SERVO HIGH SPEED/HELI'' on the tail of my REX. I have a GY240, and it works very nicely with this servo. It seems to be nice quality, has good torque and high speed. For $18, it's not too shabby
link:
http://www.allerc.com/product_info.p...oducts_id=2119
specs:
W-092SH High Speed for Mini Helicopter /E3D
Weight : 9.4g/0.36oz
Torque : 4.8V 1.3kg-cm / 17oz-in
Speed : 4.8V/0.09sec/60°
Size(mm) : 24.5x11.5x22.5
Size(inch) : 0.98x0.45x0.90
Motor type : 3-Pole Ferrite
Gear type : Plastic
Ball Bearing: Single, Top