I've tried so many. Ended up with a Noco Genius 150 3000 amp. They now have a 4250 amp model. Many that I tried said they would start a 6.7 diesel but in reality, they couldn't. So, test why you buy to be sure it will start your dead battery truck.
Also, I found that these new types of jump starters will not start a dead battery. The battery needs to have a certain level of volts to excite the jump starter. So, like djevox above, I also carry a JNC-660. The JNC-660 was recommended by a roadside assist friend who has used one for years for all of his roadside jump starting. The JNC-660 has a regular lead-acid battery to do the work. Like jump starting via another vehicle.