I've got one of those motherboards in my collection (with an Athlon XP 2600+), it came out of a generic custom-built office PC. Cheap/affordable and not really tailored towards early 2000s Windows XP gaming, though it can perform if you add a decent AGP graphics card.
I've no idea how the SIS chipset itself performs, compared with more popular chipsets such as the nForce 2 or the VIA Apollo etc, but it's safe to say that the onboard graphics is definitely a no go for 3D gaming.
If you add a decent graphics card, you should achieve your goal of early Windows XP gaming, just don't expect top performance with everything maxed out. You will obviously need to dual-boot Win 98 & XP anyway, if you want DOS too. But 1 thing to consider is that a lot of the early "XP era" games would just run on 98 anyway, so sticking with 98SE on it's own would probably suffice.