Yes, you can unlock the Duron with a pencil without much effort of difficulty I don't remember hearing anything about the MSI board- is it overclockable? The Asus A7V supports Tbirds, too, and has been a very good overclocker. Look at the Abit K7T also.
Personally, I'd recommend the Asus A7V, since that's what I bought I'm running a Duron 650@850.
Do not assume that you will receive a Duron that can be multiplier unlocked. AMD is revising all their chips so the bridge closing trick no longer works. Therefore if you get a new batch of chips you may no longer be able to over clock that way.
------------------ -=S_Klass=- I tweak... therefore I am.
You can go all the way up to 1Ghz if you are lucky on eny MB but you must deal with CPU bridges.
For the FSB problem now I must say I don`t know what to think.
On BX master they have tested ABIT RADI KT MB and it was stabile up to 124MHZ, and other MB (I think ASUS A7V) with same CPU only @ 105 or something like taht with same CPU, so CPU is not the problem but chipset.
Also on some other tests ABIT KA7, one of the best KX133 SLOT A MB, was unable to clcok higher then 100Mhz and old Irongate MSI K7Pro was able to go all the way up to 114Mhz, also with same CPU, so I am beguning to think how chipset is the problem, and u must know that chip set for AMD works in DDR mode with CPU so is much easier to develpe errors with higer frequncy, becouse data are transferd on rising and faling side of the clock.
If you have good system now I must say I would noot buy KT or KX chipset, ALi DDR is oround almoust here.
If you gonna only play games, wach movies, and things like that then you can forgot my recomendation.