Yes, you will want the butt. Plan on losing about 1/2 the weight in cooking (won't be that bad, but you'll lose lots), and plan on 1/4# post-cook meat per person. You'll have left overs, but that's not bad.
I inject my butts at home with apple juice, as bo_b_q already mentioned. I pull the meat, put it in a food saver (freezer bag if you don't have a food saver), then warm it up the following day. Best way to do that is to put the bag in hot water and let it heat up that way.
UDS is a great way to go. Go for 275 to 300 cooking temp. It will go fast and be really, really good.
When I die, my goal is to have a visible smoke ring when the coroner cuts me open for the autopsy.