As far as I know, any of the "Fuel Pack" type plug and play tuners do not work on the Magnetti Morelli fuel injection. They are available for 2001 and up, which is the Delphi type.
First thing is check the fitment of the model you have.
The only tuners for either version of the Magnetti Morelli ( 1999 is the second) would be a Power Commander, and everyone I know that has one on a Harley, has replaced on average every 4-5 years. I can only assume it is from the vibration. I know a person who had the same unit on 2 different race bikes (not Harley) for over 5 years, and it still works fine.