My asciminer sticks run on a booksize system that works great. If I was going to buy/build a low power system to run these, I'd try to find a used Atom-powered model and just boot it to the WinPE mining system. You can probably find one of these systems on ebay/craigslist for well under $100 w/o HD.
or you can run it on a maximus gene v like I do. why?
I had it left over from gpu mining. I built all my gpu miners with good parts and sold most off in june-july as gaming machines.
my cost for them was -100 to +100 bucks due to BTC profit. So selling used gamers/pc was easy sold them at about 50% off.
with a 30 day return policy. and an option to buy a fair trade warranty . everyone makes out.
If I feel like using the 2 pc's I have with asus maximus genes for lite coin and btc I can. They pull very little power due to platinum psu's.
I have 1 running 39 sticks the whole unit pulls 200 watts (all the usb sticks+ fans) with the monitor turned off.
(no LTC for the summer too hot.)