Here are some random experiences from doing the same thing on the other coast - for the DC/NoVA/Baltimore area meetings, we have a core group of about 6 who do the organizing - we email each other and figure out who organizes the next meeting. We then announce it here, on fetlife, and some other feederism related places.
We don't have a set email list, but notify people from the usual circle of attendees individually. Even after 3+ years of loosely - regular (couple of times a year) meet-ups, and regular advertising, including contacting everyone from the area we meet online or are aware of, we have maybe had 2 dozen individual attendees, and the usual meeting is between 5 and 8 people, most of whom are from that core group.
It's quite frequent that we get RSVPs from new people who are then no-shows: the old problem of the male feeder who doesn't seem to want to come out of the woodwork. Gender balance tends to be equal, or more women; mostly of us are general FAs/feedists and gainers/feedees, and into eating a lot, pure feeders are rare.
Venue criteria are pretty much the same as yours; it's usually a buffet or a restaurant with a family-all-you-can-eat option; after eating for several hours and hitting everyone's limit, we normally either drive to a dessert place, or waddle over - there is a Cheesecake factory right next to a Maggiano Italian Restaurant.
And yes, it's fun and the people tend to be a bit of a quirky and eclectic crowd.
Yes, we get stares. They are entertaining. Initial shyness went away really quickly. Those who come regularly have become friends.
Good luck getting the fatty scene going on the other coast! Hope I can make one of your events to meet everyone one of the next Cali trips.