Lowes and Home Depot sell verticle blinds. I think they cut them to fit. There should be a fairly strong frame around that slider. You will have to come up with a way to stop them from swinging when going down the road..
I understand you're dilemma,what I did on our W&P with slider, also at lowes or HD is mirror tint. I had to do both sides of the doors. It works well,even from outside at night, with interior lights on.
Just another option. I think I had $60-70 in two rolls of the tint,and the app kit.