No matter what aftermarket perofrmance muffler/exhaust you get it will drone. The stock muffler is not chambered and baffled and packed and weighs 600 lbs because Ram thought it would be cool to just do that..
Good rule of thumb is this, chambered mufflers are going to drone really bad, and resonator type are going to be a little less. But both will drone. Depending on the size of the muffler will help the drone (you have to find the balance), but it will never be non existent like the stock muffler. If you want to hear your motor your going to have to sacrifice something. The good news is, and I just stated this in another thread, is that you get used to it. So at the end of the day it dosnt really matter, unless your wife ******* every time shes in the truck.
My opinion and only real life experience with these trucks is the 22" magnaflow muffler, it droned, but was not bad, no one really mentioned it nor did it bother anyone on long trips. It was much louder than stock tho, and l loved the sound. MF is cheap, and its stainless, and I think sounds great - but again this is my opinion.