I know others have mounted their PC's directly on their subwoofer box without issues, even with a conventional hard disk. My first concern would be the hard disk, but since you are using Solid State you are OK there. My next concern would probably be the memory. I've had motherboards with very sloppy slots where the modules would need reseating if I moved the PC too much. Depending on the tightness of the slots and amount of vibration coming from your box, you may have issues there - but probably not.
I can't think of anything else in particular that would be sensitive to those vibrations. Just make sure everything tight - connections, screws, etc.