I have a Leer. It's my first Leer. I went with Leer because it was the only one available in the local area that had the features I wanted. They are made to order in the USA. You will need to go to the dealer to find out what options they have available. I didn't find the Leer web site to be very helpful when it came to details.
I went with a tonneau cover but will probably sell that and get a cap shortly. If that cap was black akmedic, it is exactly what I am looking for.
Check online, you may be able to locate a used one at a good price, There is a company in central PA Ishlers Truck Caps that sells used caps. A friend bought one there for her Silverado 8' bed for $800 and they installed it for her. There may be places like that near you. If you find one used, contact a local vo-tech or trade school and see if they would allow the students to paint your cap, it may just cost you the price for materials.
They affect it somewhat, there are big windows on the sides and the entire back is a window so it isn't too bad. I feel it is like going from a pickup to an Expedition with a cargo separator. You have to learn to use your side mirrors, maybe get small blind spot mirrors if you don't have them and trust them. Forget the mirror is on the windshield and while sitting in the truck have someone walk around it and watch them with the mirrors to learn what you can and can't see. Put some landscaping timbers in a parking lot and practice backing around them. You can take the markers for the edge of a road, reflectors on a plastic rod, and put them in the timbers so you have a height relationship when backing also.
I taught my wife how to backup using my old Dodge pickup when she had to learn to backup an ambulance. I tilted the windshield mirror up so it was useless and we went to where the driving tests are given to practice. They have 4 Jersey barriers setup for the parallel parking test and I made her park there. It took a while for her confidence to build but she easily passed the EV driving test. With practice you will get better and have more confidence, just take your time when learning.