Depends on whether you're dealing with bone-in ham -- figure 5-6 oz per person (this is hit or miss :D) you may be deaing with lumberjacks!
So, even with whole hams (bone-in) probably 20 pounds would do ya!
Southern Brethren BBQ Competition Team
"It's all about getting paid!" - Myron Mixon
"I love being hated in my hometown!" - David Hair
KingFisher Gator Rotisserie cooker, WSM, Stainless 5 burner with IR gas grill, Turkey Fryer, Weber JD Commemorative grill, slightly used Bandera chamber for future use as a cold smoker, Masterbuilt 40" insulated ELECTRIC smoker