I did not realize there were 8-core Atom server chips were a THING yet. They..are.
and check this short-case 1U out: http://www.supermicro.com/products/system/1U/5018/SYS-5018A-FTN4.cfm It has QUAD Gig-E ports. Enough for you? 20W processor? That’s better than you can find with an AMD A-series.