Need Help From A PLUGIN EXPERT Please :)

Hey, I have been searching long now for a plugin that I find very intriguing( Trying to sound smart ) Anyway to who reading i’m looking for a plugin that gives users “levels” not like editor,moderator and admin, just like Lvl 1 – 99 ( Or whatever) and say 1000 XP is needed for a next level and multiplies by a percentage each level. and posting and reading gives you experience.

Please let me know if anyone knows of such a plugin ??
Here is My Site