I guess I'm the odd person out. lol I would cook the pork myself and do it all the time. I do it in 2 roasters. I can fit 2 10-15 lb shoulders in one roaster a time. I marinate it with olive oil and a dry rub over that. (onion powder, garlic powder, minced onion, all purpose seasoning, Adobo, pepper, and brown sugar). Then place it in the fridge over night. The next day place them in the roasters and pour root beer soda over it, (only enough to cover the bottom of the pan. I cook them until I can easily pull the bone away. Usually 18 hours. Remember a roaster takes longer than a crockpot because of the air escaping. I shred as soon as it's ready, Add a small amount of BBQ sauce just for flavor. I also add some of the juices from the roaster into each freezer bag to keep the pork moist. I then freeze it until a day or 2 before I plan on using it.
Mind you the pulled pork is never the main dish at our gatherings. I use the smaller dinner rolls from Costco's. Less waist. As others have said, hot dogs, mac and cheese, Cole slaw, baked bean, corn on the cob, potato, and mac salads. You might want to consider adding in a ziti with sauce, easy and inexpensive.
Do as much as you can in advance, you will appreciate it the day of.
When my DD graduated we had 180 people in my back yard. We did all the cooking ourselves. Plus it was my 2 week post op from Rotator Cuff surgery. I did as much as I could post op. It was a huge help.
Have fun!!