I agree with solitare. If you're not careful, a Farseer will become a huge point sink and never pay for itself before being killed, as they are not too durable. Keep Mind War, and then choose either Fortune or Doom.
In 5th edition, if in doubt, choose troops. You can get Dire Avengers, or a guardian squad with a warlock, to get some more phsycers (sp) in there.