High end servos.
Ace 1015
Specifications:
Torque: 14.5 kg/cm (201.4 oz/in) @ 6V
Transit Time: 0.108 sec/60° @ 6V
$60
Hitec 5997tg
Torque: 6.0V:181.0 oz-in
Speed: 6.0V:0.14 sec/60°
$45
Hitec 7955tg
Specifications:
Speed: 0.19 / 0.15 sec @ 60 deg.
Torque: 250 / 333 oz.in (4.8v/6v)
$70
Futaba S9451
SPECS:
Speed: .13 sec/60° @ 4.8V - .10 sec/60° @ 6V
Torque: 97 oz-in @ 4.8V - 121 oz-in @ 6V
$35