Audiobook question

So I'm about to embark on my journey into the series. I see on audible they have a regular version with 1 narrator, but they also have a version with multiple voice actors. Has anyone expirenced one or the other and have any input on which is better?

Also bonus question - I was suggested this becuase I love series like Harry potter, eragon, twilight and fallen, and was looking for a similar series that also had a bit more spice since my gf is into dark romance. Does this series fit that description?