I've bought 4 cpus over the past few months. The first two, Malaysian cb0's were great, they went up to 933 at stock volts. The second two, from Phillipines were terrible. They wouldn't go past 868 at any voltage. (And that was hard to get them stable.) Unless you want to play the fleabay if they don't overclock game, I'd also suggest paying a little more for pretested and guaranteed cpus.
As another option consider the new Celeron 633, which most people (including myself) are overclocking to 950 to 975 with little difficulty. For around $80, you can't beat it.