I was going to use a Plastation VR halo-styled head strap but I've guessed that people wouldn't like to buy used PSVR just to get the strap and use it with my project.
That's why I've been working lately on my own, fully 3D prinable, halo-styled head strap.
There's also a lot of space on the front, above the display, so you might place some really weird stuff there, like a full-blown AMD Ryzen SBC.