aight, heres the lowdown. ive had 3 KT266a boards, and the only compatibility prob is with Creative soundcards, but they can easily be resolved. stick with a board from the major mobo manufacturers: asus, abit, epox, soyo, gigabyte, shuttle, and a few others have great kt266a boards. if u want a great board with tons of features get a soyo dragon+, its stable as a rock, and one of the greatest boards ive ever owned. the epox 8KHA+ is prolly the best o/c'ing board out there right now, and its cheap, 91$ on newegg.com. it just lacks the great onboard sound, lan, and raid that the dragon has.
the KT266a chipset is great, stable, and fast. the only faster chipset out is the KT333, and no boards out there utilise it yet.
for features, i heartily reccomend the soyo dragon+, if u have a sound and lan card and dont need raid, go w/ the epox8KHA+, people w/ 170+fsb's arent at all uncommon on those boards.
DO NOT SKIMP ON THE MOBO! get a notch or 2 in speed down with your cpu than gettin a crap mobo. XP1600+ and 1900+ perform almost negligibly different from eachother. but the diff in a cheap motherboard campared to one of the great enthusiasts boards a lot of us here have is incomprehensible. trust me i had a cheapo biostar board before my dragon+ and i could never get it totally stable and to perform well. a bad mobo kills the performance of your whole system. and even though your not plannin on o/c'ing now, youll change your mind eventually if u hang around here a little. may the o/c'ing bug bite'ya
Heed my words, and i hope all this rambling helps ya. I know quite a bit about chipset's and mobo's as do many other peeps here, so post any other ?'s u have
-Malakai