We have a feed room/tack room combo also. Our feed is kept in galvanized trash cans, which are in a wooden rack that keeps them at a convenient angle for me to reach all the way in – the rack is simply built out of 2 x 4 lumber. This rack is one of my favorite things in the room, as it makes my life easier.
Above the wooden rack with trash cans, there is a set of those wide wire shelves on legs, designed to be placed over a washer/dryer set. Works great for feed pans, supplement containers, bags of treats, etc., and was reasonably priced.
There is a utility sink in the corner, next to two sets of drawer units (https://www.sterilite.com/SelectProduct.html?id=347&ProductCategory=244§ion=6; ours are a different color), which are a good height to use as a work surface. It’s been very helpful to have a sink in the room, and the counter created by the drawer unit tops is also quite useful.
Next to the drawer units, there is a tall, deep set of shelves, similar to this https://www.sterilite.com/SelectProduct.html?id=196&ProductCategory=241§ion=1. On a short side, I’ve added sets of hooks to the outer edge of a couple of the shelves.
Across from the feed cans, there is a cabinet (https://www.sterilite.com/SelectProduct.html?id=195&ProductCategory=242§ion=1; ours is a different color). Next to that is a wall-mounted, multiple saddle, heavy-duty saddle rack.
Opposite the drawer units/utility sink are bridle racks, a whip rack, and hooks, along with a large tack trunk (under the various racks), and a wall-mounted blanket rack with several arms to hold blankets.
Although I originally wanted separate tack and feed rooms, this set-up has worked very well for up to five horses for many years. For ten horses, I’d definitely want a separate feed room.