What a coincidence--I added the SP hair pack last night! In your Oblivion Data folder, locate the folders containing the hair meshes and textures from Ren's Beauty Pack (I'd tell you what to look for specifically, but I can't access the PC I have Oblivion installed on at the moment). Next, open up TESCS and set moonshadow.esp as your active file (forget the ren beautypack.esp). Now, all you have to do is add the hairstyles using the same steps in the instructions you used for the SP hair pack. There is probably a better way to do this (maybe merging mods?), but I don't know how to do it. Hopefully, someone else will suggest a less time-consuming solution. Good luck!