If you've got big $$$$$ to spend on a mobo, I would recommend a Tyan (
www.tyan.com). They're bloody expensive, but if you get one of these you'll be able to keep your computer upgradeable for yonks - the Thunder series (for high spec desktops of servers) will give you trhe longest life, and will be damned fast to boot.
Their cards support all sorts of funky goodness, like AGP Pro, SCSI, etc...
• Supports up to two AMD Athlon™ MP processors
• Four DIMM sockets for up to 4GB of PC2100 DDR RAM
• AGP Pro slot, also supports 4x mode
• Two 64-bit 66MHz and three 32-bit 33MHz PCI expansion slots
• Extended ATX footprint (13" x 12", 330.2mm x 304.8mm)
Yum...
