well, none of the bitaxes have a reasonable chance of getting a block. but they meet your other criteria.
Discussion
If that was true then why did they win a block? Also which miner do you think has the best chance of winning a block that is small and silent and open source and take low electricity?
the chance of one bitaxe winning a block is around once every 3300 years at current difficulty. Is it possible? yes, but would i call that reasonable to expect to hit a block in your lifetime? no.