UPDATE 1.1: Fixed the hood not showing up for certain vampires and Khajiit. If you have a different mod which fixes this issue for the TG hood, it should work for this too. I'm not too sure actually... As stated in comments, I'm not an experienced modder; this was a personal mod which I thought someone else might be interested in, and I'm not super interested in spending lots of time updating it. However, I give free permission to anyone who wants to improve on it... Have at it. No credit necessary.

This is a super simple minimally-invasive armor replacer. I wanted to play through Dawnguard in authentic armor, but that light helmet is derpy as all get out. It's a cool design, but the implementation is bad... It makes you look bald. Ain't no way my dreadlocked Redguard was wearing that thang.

It's now called "Dawnguard Hood" and looks exactly like a Thieves Guild Hood. I prefer the style of the Mage hoods, but they clip, and the leather texture of the TG Hood looks exactly like the leather in the Dawnguard outfit with no clipping whatsoever (which is actually quite an amazing occurence, considering the high collar of the DG armor). So, TG Hood it is. Enjoy!