[Tower cases with 5.25" drive bays top to bottom...]

check Lian=li's PC-A77F

http://www.lian-li.com/v2/en/product/product06.php?pr_index=478&cl_index=1&sc_index=25&ss_index=61

I know it's a bit expensive, full aluminum though, and it takes four 5x3 drive cages (total 20 HDD),

plus you can also lay flat an ssd beneath the lower cage.

It will be out of sight.

I use the previous version PC-A77, which in addition has room for another 3 internal hdd's using its own cage

at the upper back side of the case.

I am using these Norco SS-500 http://www.xcase.co.uk/product-p/caddy-53v2.htm cages,

 

 

cheaper to get a norco 24 bay brand new than to buy the case + cages....that case looks a lot better tho haha