MKS HV380. Stick it at 12V - lovely! (0.03s transit times anyone?
)
Though more relevantly, Ace servos are good, but I'd definately recommend the Futaba BLS servos (451 would be closest to your needs). You'll find that people tend to buy one brand and then stick with it if it's successful. Any of the following with specs around 0.08-0.12s transit times, and 7+kg/cm torque would be absolutely hunky-dory.
-Futaba
-Sanwa
-Hitec
-JR
-Savox
-Ace
I'm sure there are some others too, but it's damn late.