If you build integrated, please get something that has an external AGP slot (example: i815, KM-133, NOT i810). Nothing pisses off a customer more, than being told he can't upgrade his video card (reasonable speaking, yeah I know Voodoo 5500 PCI, but they are inferior in performance, and cost more).
I suggest Duron's on KM-133, and go brand name if you can (Asus, Abit, MSI, Gigabyte at worst).