Call a local structural engineer. A licensed engineer isn't going to do calculations for you on a DIY board. Plus when you go for your permit, the township will more than likely require a sealed set of drawings and calculations. So you're best bet is to contact a local engineer.
Aggie67 is right. I like to do everything myself. Almost never hire someon e to do calculations like that, But sometimes hireing someone is the right thing to do. With a project like the one you are planing hiring a professional is the right thing to do. Goodluck