DIYable 8-16 slot 3.5" passive backplane w/ cage (into a 4u case)?

[alaricljs]

I have a 4u case with zero drive bays that satisfied its intended purpose, then plans changed. Now I need a 3.5" cage and passive backplane, at least 8 but not more than 16 disks. Preferably w/ SAS interconnects so cabling isn't crazy.

Anyone know of a good target to hunt on ebay?

 

[BeTeP]

HP DL380eG8 12-Bay LFF Drive Cage Assy New 668307-001 684886-001 | eBay (no expander, my own preference)
2x LOT OF 6 651314-001 652320-001 HP SMART CARRIER TRAY FOR GEN8 LFF SAS SATA HDD | eBay