there really is no tuner for the 3.5 croud, and probably never will be. There is the b&g tunning, but they need your computer, so that means your wheels are out of service until they get your computer back to you, Like 2 weeks nominal. Or you can purchase a tuned computer from them and send yours to them, down side is this is overly expensive, say like 800 nominal. then again you could chip your car with the jet chips, this is like 234 bones for the stage 2 in which case you will need to run high test fuel which cost more. I don't have either, so i have no idea of performance gains. I would think that chip with cai and exhaust is say 10 to 15 horsepower real world or less. Save your cash and go with the supercharger. or just trade up for the 5.7, in either case you will still have that nasty little viral infection known as the mod bug, and we all know antibiatics don't help with viral infections, so it will have to run it's course.
Diablo is working on a V6 tuner. One of the owners announced it today. No release date, and I don't know how close it is realistically to being launched, but I guess from all the code cracking they did on the Hemi it helped with the V6 code cracking.