The best CPU for gaming in the list is the 2.6 Ghz 800 FSB, on stock HSF that 2.6 will reach 2.9 to 3.0 Ghz.
If I was you I would just buy the 2.4 800 FSB and OC to 2.8. Its much cheaper to, but if your out to save money then the Barton 2500+ will do fine in games.
http://www.newegg.com/app/viewproduc...116-157&DEPA=1