The gridwall layout looks quite nice! Thanks for the bridle rack link, I need some of those!
My suggestion is to use wire shelving, often called metro shelves. Available from uline, see above link. Also at Target, Home Depot type places. Read the descriptions, mine hold over 300#s per shelf. The shelves come with WHEELS for easy moving if not TOO heavily loaded. The good part on wire shelves is they collect very little dust, unlike solid shelving. Shelf spacing is adjustable, allowing various sized containers or the drawer type containers. They come in black or silver.
I want covers on my containers to keep out dirt, though they are not see thru, so I label them with tape I can write on. Just get a new piece of tape when contents change. My first choice are the Rubbermaid tubs, various sizes, with all the same size covers. Pricy but sturdy, flexible, take abuse without damage. Waterproof! Quite a few of mine are over 20 years old, still in good shape.
I would suggest some kind of outside hangers, racks, for drying things that get wet. That moisture in the tack room makes the air very wet, might need to run a humidifier all the time. With outside racks or hangers, sweaty things, saddle pads, leather cinches, breastcollars, can air dry fairly quickly, be ready to use again the next day. Hang a couple blanket racks high up, for when you wash rugs, rainsheets, to let them drip and dry outside. Mine are on the outside of tackroom, which is roofed over with plywood to store hay on. With a usual breeze down the aisle, my freshly washed (laundromat), bulky blankets are dry overnight to take down and put away. I don’t run any big blankets thru the dryer. Saves money, plus not beating up the dryer.
Cheap, waterproof, tight sealing containers can be the supplement buckets ot the square cat litter containers. Friends may be able to supply them!! They can be covered with pretty cloth or paper for a more attractive, uniform look and hold a lot.
No pictures for you because mine is a combination driving and riding tack room, 16L x 12w… 8 Cabinets for harness dominate one wall, stuffed with driving things! When cabinet doors are closed, there is no air circulation to dry the contents. Things inside got moldy. Now doors all gape open adding to the messy look and taking up floor. I am about ready to remove all the doors. After putting up with it so long, I have lost patience! We keep boxes on cabinet tops that hold carriage lamps, heated buckets. Below are milk crates (newest favorite are the TSC black crates) holding big fly spray jugs shampoo and conditioner by the gallon, various other supplies in bottles, plus new spray bottles. Handy but out of my way. Various driving whips hang in one small corner space. I do have a bit cabinet with a pegboard back. It holds bits, watches on lanyards, rings with new snaps of all sorts, the measuring meter wheel. Quite handy, but doors are again, just never closed.
We have several big tack trunks in there, containing leather things that I do not want getting frozen or moldy in summer heat. They take up too much space, but the leather needs a controlled temp to stay nice. We have multiple harnesses that do not fit in the cabinets, MANY sets of driving reins, spare harness parts for use depending on the hitch ( 2-4-or a single) that we will be driving. Add in my riding bridles, western and english, extra girths of both kinds, latigo straps, extra stirrups and leathers, which makes for lots of stored leather things. Saddles are on one wall, trying to sell some but that always goes slow.
We WILL be sorting things tomorrow, supposed to still be good weather in the 40Fs. Husband promised to help, since the driving stuff is his!! Maybe we will have space to get around then! Ha ha
Good luck with your tack room design OP!! Oh, we have painted plasterboard walls, no paneling. Thick walls with LOTS of insulation, so maintaining temperature inside is cheap, warm or cooled. A good insulated steel door, no windows, plus a screen door to alow fresh air in if needed…