Need help, R3 vs Hemi, 6.1/6.4,,turbos??

I ran 8lbs of boost on my stock 6.4. My car was built by Arrington and tuned on their dyno with a water meth kit.It can live on 8lbs.. but that is the edge.. Get a 6.1 and put the 426 stroker kit in it. Great motor and allot of HP made from these. Arrington has everything along with Modern Muscle.