2600's with a 266 FSB are rare... very hard to find... kinda pointless if you ask me since everyone seems to want a 200 Mhz FSB. My advice is get the XP2500... you're almost guaranteed to reach 2.2 Ghz, and with the newer cores people are hitting 2.3 more often now. If you don't want an XP2500... get an XP1700 with the DLTC3 stepping... those are great overclockers... about $60 if you buy one that's guarateed to have that stepping, and you can get 2.3-2.4 Ghz out of it. I still like my XP2500 more though... and now that they're under $100, it's an easy decision in my opinion.