Sorry, I think they need a hierarchy more in the lines of Products -> Manufacturers -> Models -> SKUs. See their comment below...

I don't know if the "Brands"/"Manufacturers" (as Ubercart handles
them) are the right way to handle things, because in our site, they
need to be part of hierarchy (as oppose to a store that sells clothing
or food, you don't care to see all Nestle's Cereals, Coffees, Cookies
etc. in its own aisle, and coffee from another brand in another aisle.)
But in printer accessories, it needs to be separated by the brand.