You want a minimum of 6 channels, to allow for planes with flaps and retracts or elevon / v-tail mixing. If this is your first radio, I'd suggest you get something in the 2.4 gHz range (Spread Spectrum), as that technology has a lot to offer the hobby and will be around for a long time. I personally have 4 FM Futaba radios, a dozen receivers and dozens of servos, and the only pieces that would be usable (if I switched to 2.4 gHz) would be the servos. You, on the other hand, only need to start with the newer hardware.
As for servos, the digital servos are nicer, tighter, more accurate, spiffy, and absolutely un-necessary for anyone less than an expert-class flier. Your own reaction times are currently 1000 times slower than the capabilities of a standard servo. In other words, YOU are the weak link in your airplane's radio / servo system, and you will be for quite some time. Don't take that as an insult though, as most of the people on this Forum (including myself), whether they admit it or not, are in that same boat. However, if you have money to burn and an over-riding need to impress people (who probably couldn't care less), then super-duper digital carbon-hearted Kevlar-wrapped titanium-carbo-nitrate coated servos await the arrival of your certified funds.
Metal gear servos are very nice to have, and ball-bearing systems have less slop and produce slightly higher torque than "standard" servos.