My opinion might not count for anything but meh.
Honestly though everyone suggested is "well known" people who you see in game and know that his a really good fighter, annoying, talkative ect ect.
The best type of Admins are the ones you don't know about and only produce red text when someone is breaking the rules or when they kick someone and your left like "I had no idea he was an Admin".
I agree with this purely because if you have an "unknown" player who doesn't talk much but plays a certain game mode a lot or just keeps them self to them self and no one knows is an admin then its better because when a "known" player gets admin or is known to get people punished for breaking rules and such people tend to "behave" while their around and once their gone, all the rule breakers start doing their usual nonsense.
Tl;DR
Pick unknown people to be admins that way more rule breakers get caught and wont see who the admin is till its to late.
P.S
Siege really needs admins badly.