The mini-ITX is a via designed motherboard with an integrated Pentium 3 equivalent CPU rated at about 800MHZ. But look at the size of it! There are people putting them inside cigar humidors, drink cans, lego boxes, toasters. And all UK based.
Build your own or buy a Netbox. Here is:
The mini-ITX Store
The ToAsTOr
The Netbox home site
Netbox review