Hazey, that service already exists....
And has done for a looooong time.
Contact a Family.
Contact a Family do this routinely. More people need to use their service, exactly as you describe.
The problem with sn support is that it is so fragmented.
I think if we all start signposting to the organizations that work, fundraising for them, and bolstering the support they already offer, that there will be no need to try and set up yet more support services to fragment what's available even further.
Mn could do far worse than join forces with Contact a Family, for the type of support you are discussing. They are the ideal group to maintain a regional database of both families and provision (and I suspect, already have the majority of the database built, with some minor tweaks).
Having been on the not for profit side of the house in disability provision for some years in the UK, the most valuable part of our own service (which was a local service for disabled children and youth and their families) apart from the actual courses we ran, was the constant round robin of information that we sent to all of the families on the database, keeping them in touch with everything going on. But if you hadn't found us, you probably hadn't heard of most of it.
Contact a family already have a good reputation and are accepted by health services. A new database would be set up in competition, and doesn't particularly make sense.