Hi there,
Our previous Executive Director was a CPA and handled all financials except for the 990.
Our 990 has always been prepared with a local tax firm that has graciously donated that service year after year. I would highly suggest getting this service donated if possible, but obviously requires a good personal relationship/connection to someone qualified to do that task.
When I took the reins a year and half ago; we contracted with a local accounting practice for general book keeping (Quickbooks) and what was great was there was a sort of 'menu' to chose from with this smaller and local agency. For X service = $/month, for this service plus X = $ per month and so on.
For our staff structure and skill set of the Board of Directors- it made sense to hire a book keeper, reconcile monthly expenses, run monthly reports, etc. and then other aspects we were able to keep in house to fit our capacity and budget.
I'm not sure what- if any- help this might be, but I responded because I remember our organization being in that same spot two years ago.
Best of luck.
Keep riding and keep it fun,
Daniel