Confusion with possessives
Solution 1:
Both forms are allowed. Grammatically they work differently: The first uses the genitive to indicate that the choir belongs to, or is related to, Ako. The second uses the noun Ako as a modifier to modify the rest to indicate that it has something to do with Ako. In other words they're two different ways of arriving at the same meaning.
I'd favour the latter solely because the genitive seems to be becoming less popular in names of organisations, so the latter would be the more fashionable approach.