I would do three 1/2 size disposable pans of beans (probably 3 #10 cans + whatever your gonna doctor them up with), and 6-8 lbs of slaw. Depending on appetites (always a wild card), and the size bun you get, 4 dozen should cover it, unless your doing slider size portions. I almost always do a fruit tray, and Sam's Club sells 50ct boxes of snack size chips for around $12.00.
Craig...Chargriller Pro w/SFB, 2001 Weber 22.5 OTP, Weber OTS 18.5, Broilmaster gasser
"The Lord your God is with you, he is mighty to save. He will take great delight in you, he will quiet you with his love, he will rejoice over you with singing.” Zephaniah 3:17