I have 2 CTO's on my trailer for vending. Love em! FEC 100's would be a great choice as well. I'd say either propane or pellet - reason being most organizers of festivals don't have a place for ashes/coals to be stores and charcoal just tends to be messier overall IMO. Propane over wood like a CTO or pellets is very low mess/maintenance for vending IMO.
HTH and good luck!