LOL Holy shit, that's more food than I thought.
But i did pass by a vending machine at costco and said to myself "Hey, this isn't too bad... I could do this!" Now hearing all that, it seems worse.
Honestly, I wouldn't stop and rest if I didn't have to, because as time passes he will get more sick from the foods he has already eaten. Better get it over with as soon as possible, then get sick later.
Hey, how about if he finishes in 2+ hours, then throws up half an hour later, BUT it's still less than 3 hours? hmmm.
Seriously, no breaks until absolutely neccessary. Also, I think you should have some sort of plan but he should wing it when eating the different foods, because I know I need different types of foods to get me to keep eating more during these marathon sessions. If i alternate foods, I can keep going much further than if I kept with the same type of food.
A, 160 pounds? ouch. Good luck.