Smoker with catering question / reheat?

Well you need to get everything up to at least 140 degrees. I would not slice the brisket until it is re-heated, you will loose a lot of juice. You can re-heat the pork and brisket at the same time you are smoking the ribs, if you have the room in the cooker.

Chafing dishes and steam tables are only used to hold food at a
temperature above 140 degrees.
They should not be used to heat food "up" to that temperature.

You should heat the food up to at least 140 degrees in the oven, or
in your cooker.....THEN transfer it to the Chafing dish or steam table
once it has been heated up to the proper SAFE temperature.

You don't want to have a couple dozen Scouts with food poisoning,
from eating food that wasn't kept at proper temperatures.

If that happens you probably will never get any more business.
Plus, you may end up being sued by some of the kids parents; if
their kids get sick.

You can reheat brisket in the ovens...Make sure there is a good amount
of juice in the pan with the brisket...then tightly cover it with Foil.
Heat it at about 225-250 for probably 2-3 hours.

It will depend on how thick the briskets are and if you have 1 per
pan, or 2 per pan ...as to how long it will take.
Use your thermometer to check temperatures every so often.

If there is any way to delay the cook so the briskets and pork come off at 1 or 2 PM and then you could probably hold them at temp until 7. You can do ribs in less than 5 hours.

This thread helped me out a lot.

http://www.bbq-brethren.com/forum/showthread.php?t=10813

Do not mess around reheating at 2-300 degrees.It will take forever. Reheat at 350-400. I tried to reheat a large foil pan full of pulled pork, and one full of brisket once at 300 and it took over three hours to get really hot!