I was looking at the diablo predator, smarty jr, hypertech, or the edge. Which one these would be most suitable for a mostly stock truck like mine? I'm looking for something easy that will not cause several problems down the road. A chip or programmer that has decent power upgrades and great mpg ...

Just bought 2006 dodge diesel with 128 k miles on. I purchased it with a k n intake and magnaflow exhaust. Everything else is stock. Was looking for the best chip or programmer for mpg with the least amount of issues.