I am using a small (4"x6") SBC board with a NS Geode GX1 and CS5530 for a project. It's a complete PC on a 3.5" formfactor (300 MHz Geode, SODIMM, floppy, IDE, CF, serial, Ethernet, USB, keyboard, mouse, Video, LCD, PC/104). See: http://www.axiomtek.com/product-info.php?cat=Embedded+PCs&model=SBC84510...
The config is similar to advantech's pcm-582X series. Should be possible to get LinuxBIOS support on these.