I use Tri-Color chips from Sysco. I think I put about 3 oz of meat, blend of cheddar and Jack, melted in a broiler. I'm charging $8 for these.
I think if you are doing it for a festival, I would find a cheese warmer and use the Tri-color chips. It will set you apart.
Team: Pyle's BBQ; Yoder YS640; Good-One "Trail Boss" 60T; Weber Kettle w/rotisserie ring; Big A$$ Rotisserie; Weber OTS; New Braunfels offset smoker; Weber Smokey Mountain; Chargriller Akorn.
Saddles BBQ Bistro