If you really want this to work out, you know, planned well, all the logistics considered and addressed in advance, etc., you are undoubtedly going to have to get some guitar players involved. LOL
Bill, tgo
P.S. If you are considering the Bay Area for such a gathering, the city of Oakland has some very nice facilities that they rent out VERY inexpensively. My wife and I rented one for our wedding three years ago - a beautiful wooden lodge at the base of the Oakland Hills - holds about 125 as I recall. Big fireplace, big well equipped kitchen, set amongst trees and woods, good parking, all this for only $75 an hour! ($65 an hour for Oakland residents).