After some searching, the dell 630s as well. Found a 24x backplane upgrade kit for $108.34: HDD 24 BAY BACKPLANE 2.5" KIT DELL POWEREDGE R630 XCX10 4JJ2M 8KW2H CVJ29 4C9X1 - Newegg.comYes. On certain dell blades.
I would not let the price draw you in simply because you will be spending even more money on adapters/caddies. If you need 32 like I do that's a lot of money just for adapters.