Just my .02 but if you have never done a whole hog before this may not be the time to experiment. If you were to go the hog route you would most likely want to nail it so most of your attention will be dedicated to the cook to ensure it goes smoothly. Since this is a graduation party (assuming your son might be hitting the road soon to college or just life as an adult) you might want to stick to your comfort zone so you can spend more time enjoying the company and cherishing the moment. No offense but no one will remember what they ate at a graduation party, just the people and the times they had.
"Life is a Shipwreck but we must not forget to sing in the lifeboats"