That's a great looking truck! Welcome!
Running a higher octane will help. It's just the battle of how much you save vs. how much you spend at the pump.
Now, if you do get a CAI or make one yourself, make sure it has a heat shield. Otherwise you're completely defeating the purpose of a COLD Air Intake.
As far as the tuner goes, most people go with the DiabloSport for the Hemi's. That's why there's a whole section of the forum dedicated to it. A tuner paired with a CAI and the higher octane fuel will help you mpg's. If you can manage to keep your foot out of it with that new power
. I'm not sure how much gains you'll see, but with those three together I don't see how it wouldn't be possible to see 14-15.
Hope this helps. Good luck! Hope you enjoy the forum!