For a hard canopy I would recommend a canopy with a flip up solid door on the driver side with shelves behind it and a flip up window on the passenger side. You can look through the passenger side window of the canopy but you can not look through the driver side window of the canopy... at least the driver can't.
I really like a door on the driver side of the canopy with shelves behind it. Shelves are very handy to store a ton of stuff with really easy access and easy to organize without really impacting the storage space of the bed at all. The flip up window on the passenger side makes a lot easier to get to stuff in the front of the bed without crawling in though the tailgate.
Some people like a full height door on the back of the canopy. I prefer to keep the tailgate and have a conventional flip up window in the back.