Any V8 in a truck is worth something over a 6. Don't rule out the 4.7. I had the 4.7 in a 2002 that was bullet proof for 135,000 miles and still perfect. The new 310 hp version is very smooth, powerful, and avoids the MDS of the hemi. The hemi is more powerful, but not as smooth at idle.
If you get the 20 inch wheels, hemi with 3.92 or 3.55 is a great choice, but the 4.7 with 3.92 is a dang good package IMO.