Hi Jim, I have the WWW.Edgeproducts.com get the Edge with Attitude (gauges, defuelling all set in a package) in my 6.0 dually. I also have them in my 2001, and 2002 Duramax, all been flawless and the 2001 has over 180k miles on it and was installed when I had 5000 miles on the truck. User friendly and safe to the truck, turned 13.987 in the quarter with also a DPPI dual exhust and AFE proguard 7 air filter can. Another module is Western Diesel which my Electrician has, seems to be running also good, but not as quick as the Edge. DO NOT get the Bullydog or Quadzilla Modules, go to www.Dieselstop.com you canget alot of info there.
Boot on the board sells these, and will give you more in depth info or WWW.PMTCHIPS.com is also a OSO supplier.
Remember, in the highest setting on all these modules the weak link is the tranny, and the Torque shift has a pressure regulation problem that all these manufactures are working on to handle from a dead start with the highest power from the get go, the tranny is by no means shifting properly, and hopefully a fix will be soon. I drive in level 3 which is 80hp and then shift to 4 and 5 when rolling after 45mph, works great. Good luck, have fun, Jeff