As to uploading code, life might be tricky. There are timing issues etc that I am not sure that most radio protocols would be able to meet.
As to just getting data back and forth from a printf statement, you can probably get away with many types of radios.
I like the Bluetooth radios by AirCables.net, but others have other favorites.
I seem to recall that Kevin Watson or Mike Betts recommending
these radios once But, the remote radio is only TTL & only has Tx & Rx not all the RTS, CTS, etc. pins that a "real" RS-232 port has so I think replacing the programming cable is out of the question.
Good luck.
Joe J.