engineering for support of hole cut in roof of building

I am looking for an experienced Structural Engineer to provide engineering support for two holes to be cut in the roof of a building. This holes are for the purpose of intake and exhaust for a spray finishing booth. The size of the penetration is a 32" diameter circle. I would like to support the opening using steel angle bolted to the wooden ceiling/lid/roof structure as shown in attached drawing. I need help determining the size of the angle and number/size of fasteners needed to accomplish this goal. I will need to have an engineers stamp that will be recognized in the state of Washington to submit with my permit application. As the client, I expect a responsible engineer who will utilize the most suitable methods and materials for this project while ensuring compliance with all applicable safety guidelines. The successful engineer must be organized and knowledgeable in order to deliver a successful and satisfactory outcome. A track record of successful engineering projects within the given parameters would be preferable. I appreciate your consideration and look forward to hearing your plans and ideas for this project.