I recomend Cambro boxes vs Chafers (disposible or Electric). Keep meat whole as long as possible as will hold high temp.
The other option is to Smoke & pull / slice meat and get a comercial vacuum sealer and seal in 1 - 2 gallon bags, then freeze. At the event, keep frozen bags under ice until 1/2 hour prior to need and then submerge in boiling water or 1 hour on 225' smoker and then dump into electric chafer. Key here is to keep thickness down to 1" or less on bags. I get 2 1/2 lbs of pulled pork in a gallon (14" X 16" vacuum bag. The other issue is bag seams splitting so I seal all 3 closed sides of bag with vacuum sealer's thermal strip prior to filling.
Hope that helped....
Big Jim - Newnan, GA
Customized Lang Model 84 Longneck