Verticals are an option, but you'll need to have access to some tools. Modifying the upper valance to accommodate the slats is required. I stripped the material from the flimsy valances and made new boxes from plywood and used the fabric to cover them. Cannibalized the lambroquins (side valances) for their fabric, too. Much easier to operate, especially the big rear window. I've done the four main slide windows, two small rear windows, and the hall window.
And yes, I've posted these photos before (so sue me).