You are pretty close to both St. Louis Brews Club and STL Hops Homebrew Club. STL Brews meetings are highly attended, pretty formal, and there is a certain style rundown/tasting every meeting.
I'm in the STL Hops HBC. We have around 15-30+ people each month. Most months it starts with a share, quick club news/discussion, and a 50-50 comp at the end. Once every 3 months we have style rundown/tasting. We have a lot of fun, but we're also building up our presence by getting beers into festivals, members entering comps, big group going to this year's NHC, etc. We sort of ride the line between fun and formal.
Check out both clubs. They both have their own feel.