How about Hitec 545BB

English Metric
Torque 4.8/6.0v : 61 / 76 oz. 4.4 / 5.5 kg.
Speed 4.8/6.0v : 0.22 / 0.17 second
Size : 1.6 x 0.8 x 1.4" 40 x 20 x 36mm
Weight : 1.6 oz. 44.5 g.

Also Hobbico CS 65 :

Torque 4.8/6.0V : 5.54 / 6.62 kg.
Speed 4.8 / 6.0V : 0.16 / 0.13 second.
Weight : 49g.