I'm a BSG writer who tends to favour Starbuck, but only have a sketchy memory of reading the first couple HP books when they first came out. My Buffy background is almost nil, however, I think I did tune in for an episode or two. So, my help would be all one-sided.
Having said that, I'd hate for your story not get off the ground due to a little thing like no beta. Lots of writers don't use them. As long as you have a solid footing in the genres, you should be okay.
I'll pm you my email address so you can send me the chapters, Captain.