some advise needed

I've never done that big of a cook at once, but if I had I would definitely do the butts well in advance and freeze.  I usually don't wrap my ribs in foil but for this instance I would do the ribs on the egg for 2.5-3 hours, wrap in foil and stick them in the magic box in the kitchen and cook the wings on the egg.  Once the wings were done throw the ribs back on to finish up.

Oh and I'd figure a 1/2 pound per person of finished product.  We always like to have more than enough....hate to run out.  

Two large 9lb butts should be plenty with leftovers.  By my calculations, around 16lbs.  That is calculating 5.6oz per person.  

The butts will be fine to cook ahead and either place in bags for the next day or FTC (you have a 4-5 hour window) and use crock pots to heat.  Yes, it is not the as good as coming right off, but the rabid people at my work says it's the best ever.   After that then you can place your ribs on and then lastly, your wings.  The added space of the AR will help tremendously.  

Make sure you use a good lump that burn long and fill the Egg to the top of your platesetter.  

Gator, First and foremost congrats for taking care of your people and spreading egging love. Here are some thoughts. Know the crowd. Is this an office party at your place where your employees wear ties and ladies wear dresses. Or is this for the guys who drive trucks and work third shift. For something like this with lots of sides and desserts here is what I figure they will eat, unless we are talking about big ole country boys. 1/8 lb pork, 2 ribs per person and 2 wings. If these are nice folks who wear ties, women, and kids, than less. Remember, if they have not been to your house before they will be cautious, not wanting to appear too glutinous. If on the other hand you guys are all excellent friends and there is much camaraderie already, than you need another egg. I would say your numbers look good.  I would do Pork butt ahead and FTC. Give yourself LOTS, I repeat LOTS  of extra time if this is your first big cook. It is when you get rushed that you get out of your groove. Once out it is almost impossible to right the ship.  Remember, the actual prep takes the most time. Make a list, list every detail you can think of for every single item--ingredient list, and create a loose schedule. The last thing you want to do is go to the garage and find you are out of charcoal or you are getting ready to rub your butts down and your Dizzy Dust is empty. Keep us posted, I am sure you will be fine. 

I would happily invite @NPHusker to any parties at my place.  That being said, I am hosting a Mayweather - Pacquiao fight.  Blake, you're welcome to join.