8k3a+ is the best overclocking board out there id say...the kt400 epox board sucks in the overclocking department now..vcore only goes to 2v..and vdimm only goes to 3v..along with a lower fsb max..go with the 8k3a+
KT133 - uses SDRAM, max FSB is 100 MHz
8K3A - (KT333 chipset) uses DDR, has 1/4 and 1/5 divider so it can run in spec at 100, 133 and 166 MHz FSB (200/266/333)
comparing those 2 is comparing apples and oranges. the KT133 is a chipset. It's used in lots of motherboards. The KT333 is also a chipset... The 8K3A is just one of MANY mobos that use the KT333 chipset.