I don't think anything can be done about the name tag above you're head.
Unless we force everybody to use spout when entering the sever.
This might not be true but there was a discussion about this earlier with removing the name tags and changing names for role-play and i thought the conclusion was it was impossible without everybody switching to spoutcraft
Edit: Found it!
Earlier dicussion:
http://kiwike.se/forum/showthread.php?tid=2251&page=2
By yottabyte:
" RE: Guilds Revamped
Changing names would be very confusing, and what we can do is limited. We can change the chat names without any client plugins, that's basically it. I know other RP servers do it, but then again: very confusing when you have one name above the player and another in chat.
We're not using the plugin that changes your name.
The only possibility then would be the Spout plugins, so you can change skin and name above your head. "