Many, many people (at least five) have wanted Kalilies hairpack to apply to npcs throughout skyrim. This does that. This is my second mod and way ahead of what I tried before, so bugs are fairly inevitable, however I haven't been able to find any so far. Please tell me if you find any, and I will work on it; however, it'll probably involve extensive googling, so I can't promise any quick fixes. Any advice would be greatly appreciated because I only barely know what I'm doing. My game didn't crash and my computer isn't on fire, so as far as I'm concerned, it works for now. 
I applied the hairstyles according to my own taste; if you don't it, 
a) that's fair
b) tough
c) I will put out a guide (with screenshots) of how to restyle the npc of your choice. 

Version 1.5 - Now With Screenshots!
added Dawnguard support

I am currently completely re-working this, since I was modding very inefficiently and have since found a far easier way to do it -- this is going to take some time so sorry
also real-life stuff makes this take even longer, so this is what there is for now
I have no real idea of when the base game will be completed, however it will require all three dlc's and ks hairs

replacers like Bijin's Wives should work, as long as they're loaded after this mod
I haven't tested this with all skin textures etc, but the ones I have played with are working so far
Major replacers like WSCO *might* work, as long as they're installed/loaded before this mod -- I have not tested this so be very careful