Moab used to make a 12x13 Chinle book kit and 12x13 punched/scored Entrada and Lasal paper for screwpost binding, but currently the paper is a special-order item. Now they offer a screwpost-bound book binding called 'Flint' for horizontal 13x19. You have to make original prints to go in the binding. Pina Zangaro makes similar binding kits up to 11x14 and 11x17.
I use these kits for mock-ups and have a bookbinder make bindings with embossed covers and spines. Pina Zangaro will also emboss the covers with titles for you.
With screwpost binding, individual pages can be removed for framing. The ones I make use 12x13" paper with one inch for binding, so the pages are 12x12. Now that it's hard to get Moab's 12x13 paper, you can use 13" rolls and cut at 12".
Here's an iPhone snapshot of what mine look like:
Kirk