A butt would be perfect. 8-10 lbs bone in would be plenty and give you leftovers. There are plenty of recipes you can use in the search feature. Whatever you do, search for Chef JJ's Finishing Sauce. I don't serve pulled pork without it.
The recipe below is simple and easy. Works the same for one butt or two or three, etc. If you start now you can adapt. You can skip the overnight portion if you like. I always start my PP the day before because I get the flavors I prefer.
Ray's Quick, Easy, Deliciously Succulent Pulled Pork
This is so easy it is almost like cheating. I made it for a block party on 10/18/14. Folks didn't realize I had brought pulled pork and were chowing down on burgers and hot dogs. When they started eating the pulled pork the compliments started flying. One little elderly lady with a dish in front of her asked me if I was the one who brought the pulled pork. When I said yes she said it was great and she was on her third helping. Folks wanted it to take home too so it all disappeared.
Rubs: Any commercial pork rub will work fine. My favorite commercial rub is McCormick Sweet and Smoky. If you don't want to pay for a rub just use what I have in the recipe. You can actually skip the sugar and add it later after the smoke.
Rub if not using commercial
1/4 cup brown sugar
1/4 cup kosher salt
2 Tbs peppercorns or ground black pepper
2 Tbs New Mexico chili powder
2 Tbs paprika
1 Tbs cumin
1 Tbs onion powder
1 Tbs garlic powder
1 Tbs cinnamon
1/2 Tbs cayenne pepper
1 tsp mustard powder
Meat
16-20 lbs Pork butt or shoulder, bone in or boneless,
Post Prep
Sweet Baby Ray's BBQ Sauce (optional)
Raw sugar
Salt
Pepper
hot sauce to taste
Directions
1. Fire up the smoker with a mix of hickory and cherry wood and bring it up to 225°F.
2. Completely cover the wet meat with a good amount of the rub on all sides. (I don't use mustard or oil any longer)
3. Place the meat on a grate in a foil lined paella dish and move it to the smoker. Or put a drip pan below your cooking level.
4. Let it smoke for 6-10 hours at 225F until it is through the stall. Then put the meat in an oil sprayed 9x13 aluminum roasting pan. Add the drippings from the pan, 1 cup of fruit juice (apple cider works well), then seal tightly with a double layer of aluminum foil. Insert the food probe through the cover into the thickest part of the roast, avoiding the bone.
5. Crank the temp on the smoker up to 300°F or higher and smoke until the internal temperature of the roast is 203°F. The bone should wiggle freely.
6. Remove from the smoker, cover, and rest for at least two hours.
7. Drain the drippings, cover, and put the dripping in the refrigerator.
8. Pull the meat apart, cover, and put in the refrigerator overnight. You can add additional rub and sugar at this point to enhance the flavor of the meat if neccesary.
9. The next day scrape the fat off the drippings and add the gelatin to a Dutch Oven or large cooking pan. Heat until it melts then add a little BBQ sauce if needed. Stir to mix well.
10. Add to the chilled pulled pork and stir to coat with the melted gelatin. Taste. Add additional rub, salt, pepper, raw sugar, hot sauce to get the flavor profile desired. Salt and sugar have a big impact on the final taste. Continue to reheat until just starting to bubble.
11. Serve