I myself buy wire bead 25's at REI for $24. I've tried Conti gators and had bad luck as well as Conti GP's as far as flat protection.
As far as great flat protction. I used Armadillos (original,no race stuff). I did 5000 miles one year with not a single flat. Lots of rides through the mountains. A ride partner said they were too heavy but heck, I was training.
