Hey Kit, first off, WELCOME to the club/site, great to have you on here.
Your event sounds like a fun one.
I would recommend contacting McReynold's Farm. They are located in Phoenix by the D-Backs Stadium. They rent out Pig Roasters & you can also get your pig from them.
http://www.mcreynoldsfarms.com/Tell them AZBarbeque sent you. They will take good care of you.
Make sure to take a lot of photos & post them up here when you get back.
Have a great event, hope to see you online here more and out at some of our great events.