> I have to imagine one can find a case that allows tons of drives and is still powered by something modest.

I found it almost impossible to find a case which has a fair number of bays (at least 6), is meant for an human environment (i.e. it is not ugly or meant for a rack) and doesn't cost a lot.

So I am now working on hanging an ikea skadis on the wall and attaching everything to it. The big panel has just the right space for everything (10 disks, mobo, extra sata controller, PSU), it is ridiculously cheap, I had fun designing the parts and 3d printing them (though there are many available for free on the web) and it gives easy access to the disks and can be a topic of discussion when friends come over. Not sure it will work properly though :-) (issues may arise with vibrations, temperatures etc).

As an alternative to make it completely visible, I though about doing the opposite, hiding inside regular furniture. You can easily find metal frames meant for an "open chassis" to properly arrange motherboard, disks etc, so it is doable. The easiest would be using a regular cupboard, but I would love to use an ottoman and be able sit on top of it, a la cray-1. I "only" need to solve the issue of hiding the cable, and giving proper ventilation.