Points valid above, tho we weren't talking about Windows. Things change if you include Windows.
On the DOS side, I have a 100MHz Pentium with 8/16 MB of RAM, a Hercules Stingray Pro graphics and Orpheus 2LT with X16GS module.
That CPU handles everything bar mentioned late SVGA 3D games. Low RAM selection is due to a lot of RAM being problematic for some DOS applications and games, and 8 MB being enough for mostly everything but also there are a few 16MB requiring programs, then again there are programs that have problems above 8MB. So these two values are the sweet spot. The graphics card I've chosen by list above and availability, its strengths are VGA compatibility and clear output. The soundcard I've chosen for its crystal clear output, SB and OPL compatibility and extra features.
When I want to run those SVGA 3D games I just pull out a Core system or a P4.
I would recommend you get a Slot 1, Pentium 100+, some RAM, and a passive CF-IDE converter. Moving data around, flexibility, is important. Buy card like Stingray Pro, S3, Cirrus Logic models, consult the list above and ebay. These cards are cheap. With AWE64 you have, it's a start. Later you can upgrade with better or more sound cards.
The problem with covering dos era sound fully on a single computer is the number of ISA slots available vs CPU. You can max out a 486 board with soundcards, but 486 won't run smoothly all games. If there is a Slot 1 board with a ton of ISA slots, it's quite rare.