It really depends on the servos you are looking at, I personally would use the ones with brass or metal gears (usually higher end servos or bought as an upgrade kit). You will have to do some math on what kind of torque/power you will need to control those surfaces. Reliability will depend on lots of factors, but most RC plane servos last for quite a bit of time as long as you don't crash lol.
With My micro servos in my blade CP helicopter I had very few issues with the small servos until i crashed horribly, the crash was my fault..... after that it had chipped the gearing in the servo. In total i had about 25 flights with those servos over a year time span.
As for maintenance on the servos themselves, very little to none, but it never hurt to give them a little grease here and there.