I think it's something that would need to be built from scratch.

One thing to focus on, would be to manually verify all members before granting access.

Unfortunately, it would have to be made by someone who has the connections to make it happen. Because otherwise it won't it'll be dead.

Although, if you've made it, you got the cash to pay for advice from experts. Instead of asking a bunch random people about tax law...you can just hire a good accountant...instead of asking which vacation spot to go to, you can find a good travel agent. etc etc