I recently got a Dell Latitude c800 based on this forum suggestions. The price wasn't that bad (165€) and the laptop was in really great shape.

I installed Win98 and Win 2000 and I am able to play DOS games either in windows or just DOS. It has dual boot but win98 boots into DOS directly.

The most tricky part was to get the ESS audio to work, but actually the model c600 resource cd has a compatible win9x driver that works on DOS as well. The rest of the drivers can be from the c800 resource cd.

Very pleased with the purchased. The laptop has a DVD drive, a swappable floppy drive (i removed the extra 20gigs disk in flavour of the floppy drive), 256mb memory ( I am waiting for the 512mb to arrive) and I got the extra ATI Radeon 7600 / M6 to replace the M4 that comes with the model.