I gave it a shot , first is a wizerdy like hair and the second one is a more 70sh like flair with a little punk look, the third one...ran out of ideas .
Hoping this doesn't cause problems for you, I just noticed two things about these. First, since you're using png, go ahead and use a fully transparent background; the hair and faces are going to be layered on top of the preexisting character sprite, so (assuming I'm thinking about how this all gets coded correctly) a transparent background just makes things nice and easy. Second, take a look at the way I anti-aliased the character sprite outlines and try applying that. The graphics look nice, but they've got a little bit of the jagged-pixely look to them, which kind of works against the idea of hair being soft and/or flowing. My easy rule for anti-aliasing: each bit of jaggedness gets a pixel of 50% transparency to smooth it out. If it still looks a bit jagged, add a pixel of 33% transparency. That takes care of pretty much all problems, on this scale.
This topic also raises another issue, that I've discussed with a couple people in the past: hair animations. Certainly, when the character is doing intense motions (for example, swinging their sword) their hair is going to move. To add a further touch of realism, though, it would be awesome if the hair on a character, when appropriate (buzz-cuts do not apply here), bobbed a bit as they walk. This isn't something that would need to be attended to right away, but it would be really nice to see in future versions.