Might as well give up. The best currently available is from either Hori or PDP and most of them try to mimick the GameCube controller (whether that's good or bad is up to you). It's not like the Wii U Pro Controller is notorious for having bad ergonomics to warrant a 3rd party alternative... Likewise the Wii U just isn't there with the sales numbers or popularity to make 3rd parties interested in competing with official accessories.OK that makes more sense.
I'm still looking for a good 3rd party wiiu pro controller as I don't like Nintendo's version