It's going to depend on witch mobo revision you have. Check this link-- http://usa.asus.com/inside/techref/athlonxp.htm
That only show upto 2200+ though, but according to their latest release bios 1011(not beta), it only supports upto 2100+, so it looks like xp polomino's only.
Are you planning to overclock at all? If you are, you probably should get a 1600+. If not, you probably could get the 2200+, but I'm not sure if it'll work. Maybe you should look into getting a new mobo. They have the refurb KX7-333 board at newegg for only $49, which is a good deal to me and you can run 166fsb without anything being out of spec cause of the 5th divider, though you might have to lower the multi depending on the proc your using.