These mods:http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1282347-bspkrs-mods-armorstatushud-directionhud btw follow how to install it.
Also http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1286538-hit-splat-damage-indicators-v3-1-2-rpg-ui-and
And finally http://www.6minecraft.net/zans-minimap/ btw you can have players on on this server not sure about others