Mhhhh ...
Im using a GO TECH .25 on my CEN Truggy and the engine seems perfect to me, its a great balance between the RPM's of a .21 and the extra torque of a bigger engine, and its not bad in fuel side ... i can do easy 8 minutes to 8.30 per tank.
About brakes and servos, im not using a very expensive one, just Hitec 985 for gas/brake, its a US$ 69 servo and works GREAT, on brakes i just installed 1 disc in front and 1 on the rear and seem to be working perfect.
just my US$ .0002
cya !!