You have a few choices.
In the For Sale Area on this site is a factory Roxor All Weather Cab listed for $800 with Wipers etc. NEW. This is probably a very good buy even with shipping.
The down side is the Plexaglass Windshield, which you could probably replace with Glass Down the road.
The best available, and also the most expensive would be a Hard Cabs Full Enclosure. I have seen a Hard Cabs in person, and they are built pretty well.
I have the Hard Cabs Rear Bulkhead on mine, and I really like it. My set up is pieced together. Fortress Windshield and Top and a Hard Cabs Two Piece Rear Bulkhead. NO DOORS so far. We really need some one to step up to the plate and offer Hard Half Doors with a removable Top Section with a Wire Frame and Canvass Cover by Best Tops. We have several of these in my area on older YJ Jeeps. Most of us Roxor owners piece things together. Top, Windshield and Rear Bulkhead then we run into the problem no one sells stand alone doors.
The other option is a Rally Tops full Cab Enclosure. I have only seen pictures. I am guessing this is not a bad option either.
Keep us posted on your progress.
Bob R