Great PCI Direct3D cards are tougher to find... REALLY tough... at least on eBay. You just have to keep your eyes open and monitoring constantly.
If one of your goals is excellent DOS, you do NOT want any ATI or Matrox cards. If you DO need 3D, then Cirrus Logic is also out. The later SiS Xabre and Trident Blade3D T16 (and related versions) are pretty good but could be hard to find, even more so at a good price. Most of the S3 Savages might do the trick, but same problem as Trident/SiS.
You should be able to get just about ANY Pre-GeForce or GeForce (MX up through the FX series are good) to meet your needs in this build.
If not, then your best bet is to pair a Voodoo3 with the Voodoo1.
Otherwise, consider upgrading to an LX/BX chipset (or Via Apollo Pro+) based system. You'll be era appropriate and can still obtain cheap AGP cards with great 3D and DOS support (except ATI and Matrox, of course).
Or you can contact "Radical Vision" here. He seems to know a lot of dumb people who sells him stuff for basically nothing.