having a option in the bios and actually being able to run with those options enabled are 2 very different things.
if you want to OC in any serious manner get a board built to do the job. just about any NF2 board from Asus,Abit,Epox,Shuttle, or Soltek.
as far as what cpu is best for OC if you can find a 1700+ Tbred B with the right stepping they are hard to beat. particularly if you can get it for close to the original price, say less than $50.00. I have a AXDA 1700 DLT3C JIUHB 0310 WPMW
that will do 2400mhz on just fair air cooling.
the 2500+ Bartons are a good choice too, unlocked if you can find 1. mine top out at 2400mhz too, but the extra cache makes a diff in overall performance.