You could check my plugin suite and see if it fits your demands.
By a coincidence I'm working on a tag plugin right now that will have prefix and postfix tags by SteamID, admin flags and API + functions for simple integration with XP mods and similar. Will drop it tomorrow, at latest. Should work with most chat plugins as well as mine. https://forums.alliedmods.net/showthread.php?t=236576
but this does not have the tag in my plugin you can set any tag you want