Any of the brand name radio equipment today is fine. Futaba, JR, Hitec, Aitronics.

But I'd find that instructor first if possible, because when training he'll most likely want to use a "Buddy Box" which requires that your radio equipment be compatible. If you were in my area i could safely say buy Futaba or Hitec and there's a 90% chance the instructor will have it too. (They're compatible.) But I know other areas of the country (and probably this state) have other preferences.

You can also buy your own "buddy box" so you won't have to worry about it. Can usually be found for as little as $25 on eBay or some hobby shops.

For a name brand RC set up of 4 channels, you can expect to pay around $125 to $150. This will include a Transmitter (Tx), Receiver (Rx), battery packs for the Tx and Rx, charger for the packs, an on/off switch to mount on the plane, usually 4 servos, and one servo extension.

If you can afford a bit extra and think you'll stick with the hobby, it might be worth investing in a 6 channel (or more) computer radio. Futaba's 6EXA is a decent beginner's PC radio, and I think they're available (with all the other stuff listed above) for around $250.

Welcome to RCU, Good Luck, and most of all, Have Fun!
Dennis-