I like MSI brand mother boards.

Josh has a really nice set up on his Omnibot/vacuum project Jarvis. You could check out his thread for more info.

working my way through it now......also looking for advice on getting it up and running with EZ-B.

Asus C60 M1 AMD Fusion Dual core cpu 79.99 mini itx @ newegg.com

Excellent fanless pc. Give yourself 4gb ram and whatever hd you like. Solid state boots really fast. Use a Bluetooth sub adapter to wirelessly interface with ezb.

Pico power supply 90 watts or above will power your board from a 12v sla battery for hours.

You can pick whatever hard drive you want. This board used sata and u prefer western digital or Samsung for quality reasons.

http://www.newegg.com/Product/Product.aspx?Item=N82E16822136771

This is the hard drive I have. 59.99 250gb

Please be sure to install windows 64 bit so that you fully utilize the second cpu core and full memory bandwidth.

Have you looked at the Nano-itx or Pico-itx boards?