You need to define what you want in a DOS laptop.
Some starters to think over:
- Native SB/FM audio support
- 1:1 VGA scaling support (i.e. only 640x480 panels)
- Higher SVGA screen mode support (800x600 or higher)
- Good resolution scaling support
- USB?
- Ethernet or PCMCIA slots to add ethernet?
- Working battery?
- Built in floppy or cdrom?
- Flexible CPU speed support (Pentium MMX or a K6-2)
- Do you want to be able to run Win95/98?
- Do you want support for later, more demanding 3D dos games or those in Windows?
There's a lot to consider, and there isn't a answer which satisfies all of them.
It's worth reading through this thread: The quest for the perfect retro laptop: a saga
Personally I started with two IBM Thinkpads... Nice machines but one had a poor quality screen (DSTN) and good SB/FM audio, the other a nice screen but atrocious FM music. I have since tried a couple of Toshiba Satellite and Tecra models which have much better audio, but not as good scaling support as the Thinkpads.
It's a bit like a set of intersecting Venn diagrams with no point where every circle intersects... You gotta decide which are your highest priorities and go for that!
My collection database and technical wiki:
https://www.target-earth.net