if you have a 03 1500, I know for a fact you can run 35x12.5x 17 or 20 on stock rims with a rough country lift,
If you look at Fabtech .. they say you need aftermarket rims.
I dont remember what BDS, Skyjacker or Rancho where because it has been a while since I researched the lifts for our truck but when in doubt email the manufacture of the lift and they can tell you exactly what you need to know.