...so you want a fish-tank, but since your current place of residence disallows it for an unspecified reason, you want to set up shop in another aquarist's home, with expectation that you would have partial ownership of the tank itself and the owner of the house would either be responsible for maintenance and associated costs or allow you frequent entry to perform said maintenance?
If that is what you plan on attempting to do, I would think you'd be a bit hard-pressed to find someone willing to arrange that for you, especially an individual who doesn't know you particularly well.
I think you'd be better off waiting until you are in a position where personally owning a tank of your desired specifications is feasible.
If not, then I do agree with HUKIT that your intentions and request seems rather ambiguous and would need further clarification.
Whatever the case, I hope you are able to achieve what you want to achieve.