I have an '03 with a standard steering wheel. I was wondering if it would be possible to put on a steering wheel with the audio controls and it would plug in and work with the stereo??

You'll need the wheel (with buttons), a new clockspring, and, IIRC, programming.

http://www.dieselplace.com/forum/showthread.php?t=261427&highlight=clockspring

http://www.dieselplace.com/forum/showthread.php?t=214577&highlight=clockspring and be sure to follow my link in post #2

When I install the steering wheel and have it reprogrammed. Will the DIC work even if I didn't have it on before or will I have to buy a new gauge cluster?