"Bud boxes" used to be about the only game in
town but now there are many sources of project
cases, trying to be pretty and expensive. I used
to get most of mine at Radio Shack (RIP) just
for convenience.
I'd bet that there are many options at the usual
distributors, but I may not (and you may not)
be calling them by their "proper" name. Could
be "case", "enclosure" (though that usually
means bigger), "box", etc. If you find out what
industry likes to call them, then there are
probably many on eBay and electronics surplus
places just hiding in plain sight.