Kenne Bell makes a supercharger for the 4.7... I know they market it for the WJ'*, probably do for the durangos, too. It'* steep, though, $4000+
KRC Performance has a poopload of parts and performance upgrades for the 4.7. I'm contemplating the larger throttle body for mine. Cams, Heads, Headers, Rods, Intake, Exhaust... It'* all available.
Here'* what I recommend...
Transmission: Shift Kit: http://www.transgoperformance.com/chrysler45rfe.htm
Intake: Whatever rice pipe, cold air, or whatever you wanna put on. I do know the plastic K&N kits have a bigger HP gain than the aluminum ones, says so on their site.
Exhaust: I'm running a 2.5", with 2/3 of my cats intact. Dynomax Thrush Muffler. Maybe look for a 3" exhaust, i know Kolak has one for the WJ'*.
Computer: I have the Jet Stage II with the 180 degree stat. Performance gain? Maybe. Though I don't really notice a difference between 87 and 93 octane, so my gut feeling is that the module sucks. Get a programmer. It'll probably do a better job. Superchips makes one for the 4.7'*. KRC also has a flash they can do, and, word has it, that you can get a Mopar performance flash which may give you 15-30HP.
Iginition: NGK Platinums seem to run well, so will most other plugs, except Bosch +4'* and +2'*.