I don't think LvlUp will work yet. It was made for patch 4 and an unofficial modder fixed it to work with patch 5, but it had a lot of problems. Spells and abilities would sometimes have no icon or just blank text, there'd be repeats of spells listed, and various other issues. It did work and let you level all the way to 20, though. There was a cheat version available where it just took 1 xp to level you each time so you could get to 20 after the first few fights.
The problem is that they couldn't implement all of the class features so when you did level up, it was about half as functional as it should be. You'd still get new spell slots, HP, more attacks, etc., but not much class progression.
Apparently they fixed it for patch 6. I just installed it and it seems to be working fine. Quite a few mods have been updated to support patch 6.