I've got a couple of those old 6 ch radios that are narrow banded and they work just fine. Your problem, narrow or not, is that you are going to want new batteries and better servos anyway.
I got mine cheap and serviceable when purchased. I would NOT have put any money into them. They came along with some other equipment when I bought it.

In the long run, I'm gonna agree with Ken on the DX7. And so you will know it for your first few flights, it WILL buddy box with JR radios at your local field.

Welcome back.