Actually, I'd like some comments from you...
- Would you like a USB miner or are you happy with standalone RasPi controlled unit?
- Do you feel modular design is important, or would you prefer a nice tidy box?
- What about form factor: free or rack?
- What dB level are you comfortable with?
- Internal custom PSU or ATX?
1. whatever is cheaper and faster to develop
2. modular (there is no fun in nice tidy boxes)
3. free (kludgers gonna kludge...

)
4. very low or fairly high - very low at home, fairly high in the server room (that said, my BFSB rig is currently in the server room)
5. ATX is easier to replace, so I would stick with it