So basically a BNI (network) group for entrepreneurs/startup-ers?
So a better analogy would be - rather than a networking event where everyone exchanges business cards, it's more like a small monthly breakfast meetup where small biz owners discuss how they're growing their business, cutting cost, tackling employee challenges, or whatever else.
As for peer group I see it in 2 ways: 1. You know the people but don't have a weekly/etc. meeting 2. People who you don't know but working on building a product/company
Another thought would be more of a mastermind group. Limit it to 10 people or something and focus on weekly meetings to encourage everyone to get things done. What did you do last week, what are you planning to accomplish, etc.
Just a thought