XP Bar style?
 

I'm trying to bring my UI from Wildstar into WoW, and I've managed to get every element except for the Experience Bar. I can't seem to find any AddOns that let me customize the XP Bar enough. If anybody has a suggestion, I'd really appreciate it.

This is what I'm trying to accomplish:

Are you looking for an already-written addon you can just install and configure in-game, or are you looking for help writing your own addon to achieve this?

Either method. Preferably an already-written addon, but I can't find any that let me import my own artwork for an xp bar.

Just use your texture as the statusbar texture. jExp (outdated but should still work, as nothing in the XP/rep API has changed ever) is a simple XP bar replacement if you want a base for writing your own addon.