What do you have done as far as exhaust currently? The oem exhaust is very good, other than the restrictive muffler. If you want a tuner SC is the best by far for this engine but like said above not available yet, there is only one option. There are no headers for the 08+ 4.7L. Airram is great but they are geared more toward the pre 08 4.7L. Still worth looking/contacting him though.
Breathing in and out is good enough for me.