[qzw]

Well, one man's junk is another man's treasure.

In any case, none of the requirements you listed seem that exotic. There are computer cases with hot-swap ready drive cages, and status lights (or even LCDs) are easy to find. The software is probably already on github. The toughest ask is probably for it to be "little", but that's not something everybody cares about. So I don't find the GP's claim to be that much of a stretch.