I'd take this event all day long and for the meats and sides and tea I would be at about $19pp. Filling the mason jars with sauce, are you canning? Legal to do so? I would stay away from this if I was not. I somewhat agree with Chad's comments that you need to be careful getting into decorating and other things like rentals and bussing tables etc. Not that you should not do them but be careful because you can spend a fortune on these things. I did a wedding this summer and the rental items like plates, silverware, linens, servers, serving trays and jacks, glasses etc came to over $20 per person not counting the food.
I'd cook about #60 lbs each raw meats , 3-4 gal cole slaw, 2.5-3 pans beans, 3-4 gallons potato salad, never done okra but I'b probably do 2 pans. Tea is hard for me to figure, it's all over the place from one event to another. If beer, wine is there you will go through a lot less but I'd figure at least 16oz per person.