First you need to decide if you want to play games in native DOS. It's a yes/no decision.
Once you have made that decision, then you can narrow down a laptop to suit. Wanting a laptop that will handle XP/Vista/7 almost certainly means that it will not have support for audio in native DOS.
You *can* play a large number of DOS games in Windows, and later sound cards/chips can often support the audio requirements of DOS games via this route (though it's never 100%) - but the question of wanting native DOS support is the number one decision you need to make.
If you want something to cover the *entire* range you have suggested then you *will* have to compromise.
Some things to think about:
- Support for running games in native DOS
- Scaling support for the LCD panel/graphics chip (i.e. how well do non-native screen modes display; earlier laptops are quite crude)
- Do you want support for the widest range of games/titles in DOS? If so, then this means good quality Soundblaster Pro support, with *good* FM synthesis
- Do you want to run Windows-based games? If so, from what years/generations?
- Do you want to run Windows-based games that require 3D hardware acceleration?
The more requirements you include, the smaller your pool of options.
I'd suggest, as a starting point: The quest for the perfect retro laptop: a saga
For requirements slanted more towards native DOS and early Windows, the Toshiba Tecra/Satellite range (4xxCDT) is quite common (though with common battery leakage issues). The Compaq Armada 7xxx, 3500, 1500 all have good DOS support. All with either S3 or C&T VGA chips and sound support from ESS chips that have good DOS compatability.
Moving more towards late DOS and Win95/98 games (non-3D) you then look at laptop models with ATI Rage Mobility chips which have better scaling support, PCI audio from Yamaha and ESS. Some options are the Compaq Armada 1700/1750, Fujustu Lifebook C-series, Toshiba Satellite Pro 4xxx, Tecra 8100.
For later, Windows-only systems, then the options become more varied, with lots of later ATI video and the introduction of Nvidia, too. Sound is basically a non-issue as Windows standardises all of that for you. But the vast majority of machines in this category will have trouble playing games natively in DOS, or running early versions of Windows (lack of drivers).
The older range of Thinkpads has some models with good DOS audio (CS4237B in the 560X and 560Z, ESS Solo in the 240). I would *not* reccomend a Thinkpad with the CS4280/CS4239/CS4264 as a mainly-DOS system - from personal experience they sound very odd playing back DOS game music compared to other options (you see these in the T20/21/22 and X20/X21, late 770 and 570 models).
Honestly, there are compromises everywhere. You need to pick what your priorities are so that you are not disappointed with something that doesn't live up to expectations.
You might find this Excel spreadsheet helpful - it's a list of every model of vaguely-DOS-compatible laptop that I have looked at so far (it's focussed on later Pentium - circa 133MHz and above - through to high-end Pentium III). There are over 250 models in it - you might find something that fits your criteria?
At the very least it's a good summary of the specs of a huge range of models. I intend to put this into an online database at some point... when I get the time!