As long as your revenues and expenses match up then tax issues are not important whether or not you are a NP. If you are using cash basis instead of accrual you should make sure the transactions (dues, rent, insurance, etc.) are paid in the same period (year) if you are not a NP. Any form of incorporation would probably work here to protect the membership. Some fellows will recommend LLC, some will like a regular C for the corporate form. The important point is to make sure you form a shield (corp.) between the members and possible claims.
Do you homework and seek advice if needed from someone that practices in your state to guide you if you have questions (your buddy, neighbor, internet guy like me, etc. are often poor choices), but generally this is a fairly straightforward setup.