The '03 had two recalls of note: A valve grind on approximately 200 vehicles (out of 1875) caused horsepower to be down by approximately 25 ponies. I suspect most of these were fixed. There was also a recall for a check ball in the steering system where it connects to the cooling fan module. Again, a simple recall that I suspect most had done already. Otherwise nothing terribly major that I am aware of other than flickering lights and a slight bog on acceleration - both fixed with a computer reflash at your dealer (15 minutes).
All SRT-10's ('03 - current) have a weak pin in the differential which can cause problems if you run your car very, very hard. I would not be surprised if this design were intentional as the "weakest link" so that more major damage didn't occur in other driveline components under severe stress.
You might also note that the '04's have had a problem with loose bolts (cam, harmonic balancer, etc.). The results of those problems has sometimes been more severe, including complete engine rebuilds. If you have or are considering an '04, be sure to have your Viper tech check the harmonic balancer bolt, as well as perform the camshaft bolt recall.
Good luck in your search, and enjoy your new Viper!