Do we need a nonprofit lawyer or a real estate lawyer?

Our condominium association is a nonprofit corporation. Our bylaws state that 10% of the unit owners can call a special meeting to discuss an issue. In fact, 33% have signed a petition for a special meeting before a major expenditure is made. Counsel for the condominium association have give us an opinion the petitions were invalid. We do not agree with the opinion of the condominium lawyer, but we could easily call another special meeting with the help of an attorney who could read the bylaws and represent the unit owners who want to call the special meeting permitted under the bylaws. The expenditure planned by the board will cost east unit owner thousands of dollars. It is difficult to find lawyers who will represent unit owners rather than the condominium board.