I, too, would do the opening from the hallway. I believe you need to allot a width of 20 in. for a garment hung on a hanger. I would suggest a layout as below. The opening could be 42 in. wide.You would have a space with a width of 44 in. to move and 104 in. of easy rod access plus 2 x 20 in. storage that is a bit harder to reach (the 2 shaded areas).

Some of the closet interior companies have programs on their websites that let you design closet interiors using their pieces. I imagine one of those might work just to help you visualize things a bit more? I've also used the Ikea PAX planner for similar purposes. Just keep in mind that the dimensions on the pieces you can use will be restricted where if you're getting the interior actually made for your specific closet, you could easily tweak things to fit perfectly. (I.e. have a 19" long shelf instead of an 18" one.) They won't have a bench in the selection, of course, but you can put a shelf or basket or something where you'd like the bench top to be just to mentally mark it for yourself. Is that the kind of thing you're looking for? (For the cat litter box issue I'd probably try to put it under the bench and just be sure to allow for good access to the whole litter tray compartment for easy cleaning - probably have a door on the front with the cat access set into the door, and then also hinge the bench top some way so you can lift that up also so you don't have to get down on the floor to get into the back corners.)

I am looking at "Masonite" brand to replace my sliding glass closet doors with sliding paneled doors - (growing up in a house with solid wood doors, I loathe the hollow core too; masonite has options for core filling that make it look, feel, and soundproof more like solid). Honestly I like having the mirrors and have seen another brand on Houzz with framed glass panels that I might opt for (though there was no distributor in my area). You may seek out the door professional in the local big box store for options and/or the higher end building supply houses that allow retail customers. Good Luck. P.S. I LOVE the barn like doors on external tracts on the wall, but sadly don't have space/layout to accommodate. That might be an option for you.

Don’t have any idea of your style so here goes 2 very differnt ideas . The plain ones could be done with sheets of plexi glas the other with any fabric.