If you are hauling stuff, or towing trailers, or not, Still get the Hemi, you won't be sorry. I have the 20 inch wheels, I love them, they look so much better than the 17's, but it is just your personal opinion.

 

If you want both 4X4 and 20" wheels I would recommend the Hemi. My 4.7 performs well, but adding the extra weight and wind drag of 4X4, plus hurting your gearing with the 20"s would turn the 4.7 into a pooch.
About the tranny it drives more like a 4 spd with two overdrives, technically it is a six speed. I REALLY think it needs a 3rd gear position on the shifter, when towing this would be really nice.

 

AMEN on that! I wonder what brainiac engineer decided it didn't need anything but tow/haul? Can't wait for someone to come up with a 3rd gear only mod.......