I like the idea of other alignment Paladins. Gods should have their holy warriors. I think that a Lawful alignment ought to be required and seems appropriate. From a player perspective that really only opens up one alignment normally (Lawful Neutral), since most campaigns aren't evil oriented. But what would a LN paladin be like? Vigorously enforcing the law of their deity while steadfastly holding to the balance of good vs. evil. A paladin of order of whatever ilk. WITHOUT THE RULE OF LAW THERE IS ONLY ANARCHY.