Superhooper.org has them. Otherwise MoodHoops, Cosmic Hooper and many others will custom make one, and since it's all white it shouldn't be too crazy pricey.
Just saw Trick Concepts came out with one!
Polypro LED hoop using only solid leds of your choice...
I bought a set of white 21 LED 36" hoops from this etsy seller. They are super bright, have the same battery/ push button system as TC. Nicely balanced and super affordable.
I should add that they were a custom order, and at my door within a week. I just received a set of 3 dragonfly hoops custom ordered from her as well and couldn't be happier. There was no additional charges for custom either.