For 150, if you figure on 2 ribs per person, that's 17.5 slabs.
Quartered birds, 8 servings per bird, or 18.75.
Pulled Pork from Boston Butts, figure 1/3lb per serving with a yield of 40-50% with a clean hand-pull, so, approx. 100lbs...picnics have more bone so less yield.
Quantity for ribs is given as a fill-in, and the pork and birds as a main meat item. Adjust the birds and PP as needed for 1/3lb per person total finished product, as you should have a good mix in appetites. The ribs could be bumped up more if you were considering them as a main meat item, say 3-4 ribs instead of 2 (13 ribs/slab) while reducing birds and PP.
Good luck on the smoke!
Eric