My athlon mobo experiences.
Just ask them what chipset is used on the mobo.... KT133A is what you want, not KT133. However, all KT chipsets will run RAM @ 133 MHz. In my opinion it would be better to get a less expensive board that has a KT133 chipset and can change CPU multiplier than one that can run your athlon at 133 MHz FSB yet will not allow for multiplier changes.... Boards I recommend:
Abit KT7A and RAID
Asus A7V133
MSI K7T Turbo and Turbo R
Epox 8KTA3
if cash is a huge deal and you cant afford a KT7A, I'd recommend
Abit KT7
Asus A7Pro or A7V
FIC AZ11E
I think (I am not sure about the A7Pro) all of these boards can change multiplier and overclock. I have built Duron systems with these boards:
Gigabyte 7ZX
(1) KT7A Raid
(1) PC Chips LMR 801, the one that will do the 133 MHz FSB chips
(1) Azza KT133 based board
(2) DFI AK74 (KT133 based)
(2) FIC AZ11E
Out of all these boards I can only recommend the KT7A Raid and the AZ11E. all others lacked multiplier adjustment. All worked great when running CPU at stock speed except the Azza, which frankly has gone nuts. Something with the IDE controller. I am going to try a BIOS flash on it to see if it's a fix. The only other problem was with the 7ZX - it wouldn't properly detect a 256 MB PC133 DIMM. The best overclocker has been the Abit. (though others were built with Chrome Orbs, this one was built with a FOP32). Just my thoughts on some experiences with KT based boards.
Sickboy