Welcome to the forum, and greetings from Madison, WI.
For the windscreen, I have a Moose Racing +9" (20" total) tall windscreen, and the "Dale's nutplates" mod for mounting. It works great, and is not so tall that I am looking directly through it while riding. One issue is that it generates a large amount of buffeting right at the top of my helmet. I fixed this by buying a generic "windshield extension" off of Amazon. When angled just right, it acts as a spoiler to break up the airflow caused by the sharp top edge.
For seat, I picked up a used Corbin seat from a member here, which is a drop-in replacement with just two bolts (I still have my original seat and seat pan).
For storage, I have the OEM top box. I got the box, grab handles, and mounting hardware as "open box" on eBay to make them more affordable. It's quite a lot of separate parts and the price adds up. Additionally, I think they are discontinued by Honda for the older models. There are lots of other opinions here on good luggage options, though.