When there is a will, there is a way.
it seems to me there is nothing extra-ordinary stopping you from building your own from a GH60, or DZ60 PCB if you want to also consider split spacebar. There are plenty of guides out there to help you get started.
I built a GH60 Satan 60% with split backspace and split right shift last year, with breathing LED. I used TMK firmware to write my own layout which is way better than any layout commercially available.
Why not give it a go and share us what you end up with?