Hide Minecraft names, sit and lie down?

Um I have a little problem and although I have often seen hide and seek on YouTube and wanted to try that too. So far so good. Map to this I'm currently building. But the question is how can I hide the name above the player's head? Yes and how to sit or lie? And I mean, I do not want to go to bed or sit on chairs or anything like that?

You can hide the names with 3 commands:

/ scoreboard teams add team name
/ scoreboard teams option teamname nametagVisibility never
/ scoreboard teams join teamname @a

Sitting, lying, etc. Can you with the http://www.kodevelopment.nl/minecraft/moreplayermodels/downloads/ Mod.