I use the "If 1 meat, estimate 1/2lb per person, if multiple meats, estimate 1/4lb per person." Use the same calculation for my sides as well and it works quite well. Hotel pan size would also depend on how many it would feed, if I'm not mistaking (2" deep, 4", etc) We typically use 4" full hotel pans and get 25-30 servings out of a pan.
Hope that helps. Remember as well, as my Mother taught me "It's always better to have too much, than not enough!"