There are a ton of good Sis645-based mobos out there to choose from.
Overclocking--I use an ASUS P4S333 and can get my 1.6A to 2.4G easily. The Epox 4SDA+ looks good too, on paper it has every BIOS option you could possibly want...never used it though.
Stability--I have never had a motherboard-related crash with the P4S333. Many other manufacturers also make stable Sis645 boards, though.
Performance--They're all pretty much the same IMO. But you could wait for Sis 645DX boards to appear if you want...they will include DDR400 support.