open pavilion roof over rear patio. 16 x 14 x 12 high with 4in12 gable roof legdgered off of rear wall of home. 2 post only

I am looking to have an open pavilion roof built over my rear patio. The size of the roof is 16 x 14 x 12 feet high with a 4 in 12 gable roof legdgered off the rear flat wall of my home. I would prefer that there be only two posts for the structure and minimal rafters. For the materials of the roof, I prefer to use 3/4 plywood decking and asphalt shingles and for the foundation of the posts, I would like to use concrete. As for the design, I am looking for a classic style, open and simple.