There are lots of possible examiner qualities candidates might prefer – an expert, someone you’ve cited, someone relatively new – but all of these are just preferences. There’s no right or wrong preference: it’s just how you feel. Reflect on your preferences and make some suggestions to your supervisor. See which names surface in the discussion.
My only other piece of advice for candidates would be to aim for examiners who aren’t strangers.
Aim for an internal who you have spoken to before. Aim for an external you have met at conferences. Aim for people who aren’t big question marks when you think about them and their work. Knowing even a little about your examiners can boost your confidence a lot for the viva.