I'm using Hitec servos
HSC-5996tg for t/b
torque @ 111oz
speed @ .10sec/
HS-5995tg for steering,
Torque @ 333oz however this one is discontinued and the up dated one is the HS-7955TG.
These are what I use for my xray 808. Hitec has great customer service along with a good warranty. If you have any problems with them make sure you save your receipt.
I recently got the HS-7955tg which I will be using as a back-up servo just in case. When buying servos you might as well go with the best.