I guess you are thinking about a 4-5 lb 40 size plane. You didn't say. I have flown 3 of them for a couple of years using standard servos - usually Hitec 325, 425 with no regrets. I have used 700 mah nimh batteries also. The idea was why spend lots of money to get a light engine then use a battery that is way heavier than rqd. I always recharge with a charger that tells how much juce it took to refill the battery and seldom need more than 250 mah. However few things are less fun than runnig your battery dead in flight. So be careful.