1- Metal is also available but easier to mess up IMO. You can put strips of vinyl made for the purpose about 2" wide in a field of wood or plywood. You can drill holes in wood or plywood and screen them. You can use narrow boards and just leave one out (staple on screen first). Probably others I can't remember or haven't seen.
2- What is already built? Do you have rafters coming down and that's it? The horizontals haven't been installed yet? Do you want a horizontal soffitt (Most do)? You'll just install the soffitt up against the brick after you've built whatever framing you'll need to support it.
3- Your fascia is usually an inch or two below the soffitt, so whatever that works out to for your roof. As to what materials, that depends on your taste, your budget and your wife.