I bought a used Chenbro SR209 server case that came with the standard full size 4-drive cage, with a hot swap SATA backplane, but no drive trays. I looked on the chenbro site, but I couldn't find the trays separately. Are hot swap trays at all standard as far as fitting these things? I see a lot of HP and Dell stuff available on Ebay for cheap, but I don't know what will fit. This is what mine looks like.