Is there such a thing as a good solid, 2.5 inch enclosure...

[cbelt3]

I've used an enclosure that are made of two pieces of extruded aluminum and the 'cover' just slides on and off. But there are screws that hold the PC board to the backplane. It was a cheapie sold at MicroCenter, no idea whose. I'd go there (or equivalent) and open some boxes and take a look at how the enclosures are made.

I assume you want something to slide drives in and out of.