I goofed on my specs . It holds 300 pounds of feed and it is a 55 gallon barrel , but it is thick ( probably indestructible ) plastic and you could cut it to the height you would need. If you look on CL or other places you can find them cheap. We got ours for 10 bucks each ( with lids and locking rings). They used to hold tomato sauce. They will have a label on them saying what was in it and of course you want something non chemical.
As someone who bought hay hoops for my entire farm for in the stalls. Then the junior feeder for outside in the sacrifice fields. Both of which I was very satisfied with.
I had one horse who was pawing a lot and we bought a porta grazer! Hands down the winner of the 3 options! Junior feeder is a close second but the safety factor seems higher on the porta grazer and by the time you ship them the cost is only about 50$ more for the porta grazer.
If I had to do over I would buy all porta grazers for inside and out! Slowly replacing the hay hoops with porta grazers for the fussier horses.
You may also want to check out HayBar. I like them more than the item you posted b/c they are raised a small bit off the ground-- this allows the chafe to fall to the ground and is easily cleaned away when you do stalls. Haybarusa.com
Porta Grazers are great in a stall. They fit nicely in a corner. I have 12 x 12 stalls and I don’t find them intrusive. My horses do play with them, though, so if I want them to stay in the corner I tie them to the wall with a hay rope. I generally just leave them loose though.