There are a WIDE range of options, mostly by reputation. Top online ones you usually see are Hemifever (Sean), Inertia (Stu), Jay Greene, Diablotoona, etc ect ad nauseum. My personal experience is with Hemifever and Inertia, I would go with either one myself. I suggest doing a search through the site for "custom tune" and see what you find to help you make a decision. Regardless of who you pick, you'll either need a Diablo tuner (or in some cases you can buy it through them, Sean actually offers them with his tunes loaded) and you tell them what you have (total combo), what you need (in your case, mainly turn off MDS and EGR, customizing the tune would make it more fun to drive) and intended use (transport, any towing, etc) and they'll email you one for you to load and try out, then tweak it from there if necessary. I'd also try to take advantage of any trans tuning that can be done as well. If you have a reputable shop nearby they may also be able to do it locally without you having to buy a tuner, though the thing to look for in this case is Mopar/hemi experience. Alot of these shops do mostly Mustang or LS work and try to apply the same stuff to hemis (doesn't always work out that well).