daveg - yes, although I've been back-and-forth on exactly what to use - oil or poly. The current reigning idea is GF exterior 450 stain followed by 450 topcoat.
pottz - yes, the plan is for a store-bought outside cushion set. I did my sit tests with one, but its cushions are too thick, so I'm on the hunt.
For being a knock-down design, it is pretty sturdy. I'm anxious to start the 2nd one, although last night I found that the pieces I had rough-cut out last fall had shrunk across the grain, so my template routing is likely going to leave some patches that don't get hit by the router. They'll need to be finessed by hand. I'll make it work, but it's not ideal.
I finished the template routing for the 2nd chair components this evening. Despite the shrunken blanks, it all went pretty well. I’m looking forward to a productive weekend.