Zotac ZBOX ID91 Mini PC (Intel Core i3-4130T / 500GB HDD / 4GB RAM)
Recently installed Windows 8.1 x64 on this device and replicated my SambaPOS 4.1.82 setup to the machine, using SQL Express 2014 x64. Working great so far - quick, quiet, small. Besides SambaPOS, it also serves up music for my shop and IIS/PHP for the Inventory System.
I got it for $460 CAD …
Amazon:
http://www.amazon.com/Zotac-i3-4130T-2-9GHz-Barebone-ZBOX-ID91-PLUS-U/dp/B00FN5ZK6Q