I stopped at Petco to see if they had a hay manger. Their in-store selection was the worst, for rabbits at least. So back to Pet Supplies Plus.
Now that I am becoming more familiar with rabbit supplies, Pet Supplies Plus and PetSmart are on a par with each other. The hay manger was not as successful as I had hoped, as the bars of the cage don't line up with the tabs on the manger, so hay leaks out the bottom. But it takes up no cage space. I will try modifying it to minimize the leakage.
And since I was in the pet store, I checked out what else was there and ended up buying a shelf to give Hip Hop a little loft, which she has totally ignored, plus some fruitwood Bark Bites to add to the kabob, which she has also ignored, plus another grass mat, for the bed (Hip Hop approved). And I think that's it.