ORIGINAL: RCKen
The reactor bipe should use standard servos, stay away from the minis for this plane.
As he said. Standard Servos are fine.
You CAN use "high torque Mini" servos though, but not anything smaller.
Mini servos look slightly smaller than standard size servos, and if you go with higher torque minis you'll be fine.
As RC Ken states, I would AVOID "standard" torque Mini servos though, as this plane has large control surfaces.