The DR-DOS/OpenDOS Enhancement Project

You would probably also be interested in the old Toshiba Libretto. Nice little machines, designed for Windows 95/98 so they were necessarily DOS-compatible. Most had Pentium processors and 16 megs of RAM. You can still find 'em on eBay. If you're interested, make sure to get one with the Libretto floppy drive included -- a DOS machine with no removable storage is a sad and useless thing!

An old page, but still useful: http://www.silverace.com/libretto/