Welcome to LGM, Min.Moore!
Have been thinking off and on of organizing one. There is a need for Christians in our area to get together and outreach to the community.
But I have to count the costs, like in Jesus' parable of the man building a construction project. IMO, the obstacles would include getting people to contribute and cooperate, and staying out of the way of local churches who would give us the side-eye for trying to co-op their choir members.
There is a community/University choir in our area, but that is more secular and Classically oriented, though they do some christian material. They are organized as a 501c non-profit and do relentless fundraising. There are also Barbershop and Classical/Pop groups, but no community Gospel choirs, aside from the rare interchurch concert. The other choral groups involve mainly the older/richer in our community, not the majority of the local population.
If I did go through with this I would get input/help from others, and probably start with a smaller womens' group...but pray for me, networking is not my strong suit...