I have two sons, both with TQi radios. Same situation. If you want to upgrade on the cheap, the docking bay helps a lot, I really hate the little light button system.

If you want a quality racing radio on the cheap, but with good features:

Futaba 4PL
Airtronics MT-4

I would recommend the Futaba over Airtronics, due to the less expensive relievers. Both are great radios.