Both good points! I would agree with leaving it the coop level but then again, I imagine that will totally confuse new customers. They’ll come to the meet.coop site and then when they get to the sign-up page, they’ll be confronted by the fact that they need to investigate and find a co-op that works for them and re-sells the meet.coop BBB service.
One attempt to solve this that I have seen is the Welcome to the CHATONS website | CHATONS “find a service provider” form: https://chatons.org/en/find (unfortunately in FR but you’ll get the idea). CHATONS is a platform for a whole bunch of service providers and users can find the right one that works for them from there. I can imagine we could emulate this type of form with a few simple buttons which then selects a provider and takes them directly to their sign up page? That would take some coordination but might work…
Another approach is the “pick a mastodon instance” site for https://instances.social. Not very fancy but you can also get the idea here. Guide the user through some basic questions and get straight into sign-up.