Early day yet but 19 willing members , See what happens later in the week
My thoughts on this would be a venue with rooms for over night accommodation , arrive Saturday , book in , meal , meet and greet , few beers and a chat , If the venue has a medium conference room each member would be allocated a time slot for setting up and running their system, then all change onto the next members system etc
Central location should please everyone , very early days yet and 19 people may not work , Time will tell
These are just my thoughts
If we end u with 70 members maybe a room based show like WW