Managed to get it installed and also with the correct video kext after trying a few..
Only issue I am having now, is that Clover isn't installing into the boot sector, it claims installation completed, but when I reboot, I get the Niresh boot loader, which fails with 'mach_kernel' not found. I did try Niresh ahead of the virgin method in this guide.. Will nvram -c sort this out and allow me to install clover?