I think the OP said that he bought a Socket 370 / VIA 686B Gigabyte board for the Tualatin.

I separated dos/win98 build and I also built a system for win98/winXP. Main thing I have noticed is that early winXP games also work fine in win98se, so I can run them in dos/win98 system. Also many dos games do work in my win98/winxp system that has yamaha pci sound card, but sound compatibility is not perfect and also I noticed that on the newer motherboard a lot of the UMB are in use already by the motherboard and that means I simply can't load many of the larger drivers like optical drive drivers/mscdex into upper memory and that prevents me from running some of the dos games that require more conventional memory while needing a cd in cd-rom drive. If you want better compatibility it is better to have multiple systems, but if you only care about specific games that you like you can try to put all 3 in one system and see if the games you like all work.