I have Mystica and it's really good but as you said, it's a female choir. If you want a complete choir then take a look at 8dio Requiem Pro or something bigger like 8dio Lacrimosa Epic Symphonic Choir.
This is correct. I have Cantus and Mystica. If you're after religious/gregorian/or even medieval then it would suit. It's well sampled and sounds great and 2 for 1 at Best Service is good value. However, if you're after a more traditional female choir I would definitely recommend Freyja. I don't have Árva or Wotan...yet (but I'm expecting that to change soon).