We need a new banister, and would like something unusual - not overly modern...was thinking maybe iron, or is that too complicated? Any advice would be appreciated! Was hoping to find one in an old house, but that won't happen!

To fit one on an existing structure will likely be expensive as it needs to be custom made. If you want iron, look for a metal artisan, they do this type of work although it won't come cheap. You may also consider replacing the whole structure, may be cheaper in the end.

I suspect you'll need a carpenter and this will cost you a small fortune. good luck with that!