Yeah, if you are getting into flying, Id get a dedicated flying radio and either keep your current radio for land vehicles, or upgrade.
I got an MX-3 with a used Savage I bought. I have to say, the MX-3 was one of the most attractive parts of the deal, because all I've ever used is the stock RTR radios.
As far as heli's, you'd be better off with a 2 stick radio, with more than 3 channels (I think 6 is standard for helis). When I had a plane, I had a 2 stick 5 channel radio that was perfect for a plane with ailerons. I know helis are a bit more complicated, so theyd need an even more complex radio setup.
-Chris