I think you will find the 165 degree hinge should be enough to clear the curtain pole and window sill, these people seem to do a reasonably priced one, it's H068B half way down the page.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!