Generally I steer away from Via unless it’s my only option (e.g. for price). If you want to OC your CPU then I’d look to other brands and then maybe Via, but for not OCing it the best board you could do would likely be one of the AMD 760 MPX chipset based ones, expecially the Tyans. It has quite a few unique features such as support for 4 Gb of RAM (3.5 Gb useable … this is the physical limit on the Athlon which does not have any form of PAE), 64 bit 66 MHz PCI slots, optional onboard 3com LAN (even GoC), optional onboard SCSI, et cetera. Really a killer board, if you get the idea, and it will take a single XP just as well as dual MPs.
Oh, and BTW: if you do go dual MPs, you’ll never turn back. Ever. You will loose a slight bit of gaming performance, but you’ll appreciate being able to run a game server and join it from your own machine with no slowdown, all while you’re burning a CD and playing a DVD that’s running on your TV. Yeah, dual systems can handle that much load and still feel more responsive than your single XP 2600+ provided the rest of your hardware is good (e.g. 7200 RPM or faster drives, enough RAM, good video, etc.).