Ik zag op Overclockers.com wat info over de PII-300, PII-333 en C300A:
PC Nut is confirming that PII300s are about extinct - no new supply; inventory is low and limited, so if you want one you will pay a premium. C300a's are now best bet for overclocking to 450, but newer chips are failing at about a 25% rate, so pre-tested buying may be the only way to go. I am collecting data on c300a's and hope to have it up soon.
As for PII333s, I am getting news from ASETEK (Danish company selling super-cooling cases) that SL2QH week 39 is running 560 out of the box. This is a stepping 1 version and I am surprised at its performance. I can only urge that if you can try these out before buying, you may get a nice surprise.