There are several different personal preferences for this one. In general, bring to room temp then you could cook anywhere from 225 to 300 (even 325). I typically start mine at ~250 for about an hour then increase to 275 and finish there.
As for the time, the old saying goes to cook to the temp, not time. I cook mine to ~195 then rest for at least half hour. It also finishes really well resting in a cooler. That being said for planning, the cook time at this temp is roughly ~6 to ~7 hours depending on the meat.
I know you mentioned cooking about 100lbs. In general for bone-in, I typically plan on a 50-55% loss (bone,skin,fat) so that should give you about ~45-50lb meat to pull/shred. That should give you about ~180 4oz servings, ~120 6oz. Again, just estimates.
I hope these guidelines help. Of course let us know if you have any other questions. Please take a pic and post your results when done!
Donald