We had a large window like that and chose a pleated blind…one…that covered the whole window. Ours had some coating on the window side that helped block heat, sun, drafts, and made the blind more opaque. However…it still did let in some light.
When it was down, it came right to the window sill level. When it was up, it was about 3 inches deep, and just blended in.
If you need something more “durable”, you might want to consider plantation blinds. They are sort of like old Venetian blinds, but are made of wood.