i hope!!! i looked into spit-roasters and they are very expensive. i imagine you’re not in the market for one unless you’re planning on doing this often! This seems like a pretty big project according to what i've read but anything can be done with friends and the right amount of beer! lol
I don't know whether you've done spit-roasting before but i found a comprehensive guide from selecting the carcass to cooking it beginning to end.
Spit-Roasting

"The choice of the carcass is of utmost importance if you want tasty and tender meat. Old, heavy carcasses not only take longer to cook than younger ones, but also turn out dry and tough. Make sure that one you select is that of a young, well-fed animal."
"The most suitable weight for a pork carcass is between 30 and 50 pounds."
"As a general rule a dressed animal will yield 50% of the dressed weight in cooked meat. You should allow ½ to 1/3 of a pound of meat per person, depending on how savage your friends are."
Just to give you an idea of how much these roasters cost, here is a website that sells them:
Pig Cookers from Meadow Creek Barbeque Equipment | Yoder's Smoky Mountain Barbecue
here is a place that rents them in Pittstown which is a 2 hour drive from where you are. maybe you can find a place that's closer but at least you know of this place if all else fails! you can rent it by the weekend ($150.00) or for the week ($250.00).
HotDesign.us – Family Size Whole Roast Rotisserie Grill

this is the roaster you will get. they also give you tips on the website such as:
"HINT: To roast a 50 lbs. pig it usually takes a total of 30-40 lbs. of natural hardwood charcoal."
"HINT: To roast a 50 lbs. pig it usually takes about 5-5 ½ hours. Increase time for a stuffed pig. Do not rush by increasing the temperature. You take the chance of burning the skin and the ribs. The shoulders need time to cook to the bone."
"The rotisserie grill is designed to accommodate a 50-65 lbs. pig."
you really need to visit the website because it will tell you all you need to know about their rental policy, etc. Good Luck! i hope this helps you! it sounds like a blast!
