If stability is your key factor, go with the Tyan S1854 Trinity 400. I have built many, many systems using this board. It is not much of an overclocking board, but at 'standard' bus speeds, it is the most stable PIII board I have ever used (more stable than any BX board). The Asus P3V4X is also a decent board along with the Abit VT6X4 (I'm still using one of these today).