There are several vendors on this site that sell EFILive tunes.
You can get a turbo-back exhaust and a emissions-delete tune, but depending on where you live, that can cause you to be unable to smog/register the truck.
I know at least IdahoRob / Adrenaline Truck Performance sells emissions-compliant tunes that keep the factory exhaust. Heck, he has [THREAD=63908]a 2013 LML running over 500 HP with all the factory emissions working![/THREAD] Other vendors might be able to do emissions-compliant tunes as well.