Outer Limits 4x4 Board

looking for a power upgrade for 3ltr td 4cyl gu`s,
any opinion`s on d`tronic or tunit or are there any other plug in mods for this engine,
& will they shorten the life till total failure??
need help asap!!!!!
also anyone selling any power upgrade units??
also open to any other possibilities....
the end result im looking for is more power, fuel economy & overall better drivability.......
it will be doing highway miles with a trailer full of dive gear.
cheers all
daz
newcastle

Ive had a dtronic for nearly 12 months now, awesome performance both when towing and offroad, no where near as laggy, especially with the a/c on