This is a lovely house but I can see why you want some kind of covering over the door. That said the arch window above the door does hamper what you can do. If you put the covering above the arch window it sets it so high that it may not do much good. Probably your best bet for function is to add it between the arch window and the window above the door, but it will block out some of that light and may look like its crowding the door. One idea comes to mind is maybe some kind of arched canvas awning instead of a permanent roof structure ? Or possibly repeating the copper seamed roof look you have over the front bay window ?

The two bay window flanking the entry may hinder the construction of a portico.

Wondering if it would be an option to have the soffit extended out more from roof to protect the area below more, without occluding the windows. It would not really be a portico but more of an extension out from the roofline....Just a thought...

http://houzz.com/photos/507770

http://houzz.com/photos/1288888

Extending soffit is complicated by leaves that clog gutter screens in the fall, so I've ruled out that one, plus it would look a bit odd.
I can' imagine The narrow porch and the bay windows coupled with a tall brick style portico. Would look wired.
The copper awning idea directly above the door with iron supports or accents is a great idea. Thanks for the pictures, because they help me imagine how it would look on my house. I'll share pictures with contractor for design and construction.
Thanks for the great comments and ideas. This houzz.com website is fabulous.