I understand that not all the names people want will be appropriate, so members of staff could just have a quick check to see the player's chosen name is. The rank will only come with the /hat option. The colour of the Rank may be chosen by the player.
You could just make it as a custom prefix which can be moderated by the staff and only cost a few dollars.
You can have custom prefixes/suffixes for several years now, they come with the small UDP 1, check here fore more info https://store.ajgaming.net/category/946230 @SlashingStorm