Hallo mark,
I have compiled nvidia, intel and radeon (amdgpu) into my system.
You can take a look at it:
http://centos.cms4all.org/repo/7/drivers/
I run my machine with the current stable kernel 4.8.15
http://centos.cms4all.org/repo/7/kernel/
For some tests i run winehq and other applications so far.
with my mesa built 13.0.2 + LLVM 3.9.0.
http://centos.cms4all.org/repo/7/mesa/
Tested in the past with radeon 6870 and today r9 280x.
Sincerely
Andy
They not signed - private work(around) -, but the sources are there :-)