Originally Posted by
whomhead
Toughness is not an option for the fighter bonus feats, so that's probably not happening.
To the OP: I would first ask why you want to take a second level of fighter? The 19 cleric, 1 fighter split is a great build, and you may be losing more than you gain by splashing a second level.
If you are intent on a 2 fighter splash, then I would second the suggestion for Improved Critical for your weapon type. That will do much more for you than any of the others, though Cleave is a good alternative.