I would definitely recommend a good cold air intake. I had a Dakota R/T for a few years and the only chip or computer worth having was either a custom flash or a MP PCM. No one really had much luck with the Jet chip. The Hypertech wasn't available back when I had my truck so I don't know much about it. The downside of the MP PCM and most chips is that they require you to run premium fuel, and with today's prices thats a big negative.
If you have the money... beyond a cold air intake, a 50mm billet TB from F&B is a good upgrade as well:
http://www.fbthrottlebodies.com/ Otherwise, the Fastman has some ported stock throttle bodies, or you can try porting your own:
http://www.thefastman.com/Throttlebodies5x.aspBe aware that cam and bigger injectors don't work too well with the Magnum engines, due to the lack of being able to control them (no MAF and no computer tuning software). Other than that, I would recommend a tune up (Autolite 3923 plugs, new cap/rotor/wires) and be sure to check and make sure your manifold belly pan gasket is not leaking oil.
Travis
72 Cuda