If you're looking for one that will fit an Xbox controller, I recommend this one. Fits the headset, Oculus controller, Xbox controller, battery pack, portable wifi router, and cables for all these. And it's almost 2/3 cheaper in cost.

This one fit my Go, touch controller, Xbox controller, and a battery bank no problem.

I got this one - works great and holds a battery power pack as well.

https://www.amazon.com/gp/product/B01DVMTJQE/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Accessories like this usually takes time to roll out after a product does. They don't want to have a ton of accessories for a product that might flop. So I think this is a good sign that the Go is selling good (which I didn't have any doubt on anyway - This just confirms it even more), and hopefully we see more and more accessories released.

As for this case, I still recommend the one I bought over this to anyone looking, though. If we go by the German Alternate.de site and the UK Amazon site listed in other comments, it's around $45 for this case. The one I got is only $17, and holds more. Not only can I put the headset and Go controller in the case, I can also fit an Xbox controller, battery pack, mini wifi router, recharger, and all the cables in my case, which the pictures for the "official" case doesn't look like it can handle.