The fitPC is a n off the shelf item:
http://www.fit-pc.com/web/purchase/order-direct-fit-pc3/
We have a fitPC2 and fitPC3 here at work so I have had a little play with different options.
Settings available which make it ideal:
Startup on power (ie ignition on)
Power off when power is removed (ie ignition off). In this mode it doesn't write files to the cache or something so nothing is lost by pulling power. Computer geeks may be able to expand on this one. It's a setting in BOIS. Obviously only good with a SSD.