Back-end WordPress developer with eCommerce experience

Small non-profit looking for help with website maintenance and security. We're looking for someone with WordPress expertise to assess plugins for suitability, assess security and general web behavior, troubleshoot issues, and oversee eCommerce implementation. You would work as an independent contractor, variable hours depending upon need, but est. 5 to 10 hours/wk maximum. Rate: $30/hr, negotiable and subject to raise.