Another option which I really like but is a little more complicated is to change the name of the turn undead ability to to something like divine power. Every cleric has a pool of divine power from the deity which can be used to power turn undead, divine feats and the abilities that we give the cleric such as stunning fist. This pool should be calculated like the turn undead is for the # of times a cleric can use it. That way we can have abilities like the one Tfop has in place of turning undead that doesn't have to rely on the # of turn undeads and still give the cleric access to divine feats.