One thing I found in my search besides deciding if I was going stickburner or pellet....pig roaster or offset, etc. I figured how many people I typically cook for 90% of the time...then I upped the number by 25%-40% to determine what size I needed. Originally wanted PR36 or SQ36....50# pigs made me go Pig Roaster styles....and doing the math and adding some growing room moved me from PR36 to PR42.
I found that the more I smoked and shared my results for input and criticism...the more that wanted to come over and eat.
I have found I can cook a 100# hog on my Meadow Creek PR42.....6 racks of pork spare ribs uncut.....4 full pork shoulders (butte and shoulder)....can usually squeeze 24 wings on there as well with the ribs and hunks of meat as I have fallen in love with wings with my dry rub on them. :)
Anyhow....for the money you have I would look at what is going to give you the most bang for the buck whether new or used...has the best reputation for quality...and holds its resale in case you decide you want something larger and wife wont let you keep both. LOL
Anyhow....account for more people than you currently expect wanting to be fed when you start and they start tasting the meat......smoke it and they will come.
If I did it over would get PR60....as I have maxxed it out on ribs and shoulders already for get togethers....so if I go over 24 people I go to whole hog instead of ribs. LOL
Good luck and let us know what you decide.