I think this can be interesting to you. There is no single picture of the product new product, cyberfaceX, but they show the huge lenses and displays they are using for cyberface2. They are intended to achieve a really big FOV with a single lens and display per eye.
I abandoned the idea of a selfmade HMD long time ago. It's technically too advanced to built anything practical without high tech materials and machines. The only path is... money, big amounts of it.