Argonath RPG is working on a LU server that will be a RPG gamemode, however it will not be strict/"real-life" roleplay.
It won't be released to others, though.
The problem is that RP/RPG/roleplay servers all have their own, specific style of roleplaying. That's why you rarely see pre-made gamemodes for them in any GTA multiplayer mods. The ones that are released are usually either stolen, or they are copycats of someone else's.