Superchips has the best tranny tune on the market for '04+ years. You can adjust set points for 1Up, 2Up 2PUp, 3Up, 4Up, 5Dn, 4Dn, 3Dn, 2PDn, 2Dn. Also has Torque Management adjustments for WOT for 1st, 2dn, 2ndP, 3rd and 4th and, Part Shift TM for 1Up, 2UP, 2PUp, 3Up and 4Up.
As for which tuner to purchase, that will depend on your long term plans for engine mods. If you have NO plans for major engine mods (CAM, Headers, Supercharger...) then Superchips will fit your bill. If you do have plans for major engine mods then as, Al said, the Diablo Trinity or even SCT will be what you'll need as they offer custom tunes that SC does not.
I've heard from several sources that Chips are not worth the silicone they're printed on; you'll want a programmer.
As for increased HP and Torque, or course a programmer but first you may want to invest in a Cold Air Intake and a better exhaust system to get that Hemi breathing correctly.
I gained 1.5-2.0 MPG by adding a Banks Monster Exhaust CAT-back replacing my Flowmaster 70 series - which rusted through in less than 4 years.
One thing I forgot to mention: There is currently NO programmer/tuner support for 2011+ year CHRYSLER trucks, cars and Jeeps. Chrysler does everything in their power to prohibit third party programmers from writing to the PCM. Starting with the '11 year they implemented a revolving encryption routine stop third parties from updating the PCM. Superchips and Diablo are working to reverse engineer the encryption routine but so far they've been unsuccessful. I believe they may be getting close but they will NOT commit to a release. Which I cannot blame them.