Just an update on my hack status-
After trying this build with high sierra and failing, and realising with the help of the forum members that my RAM was falsely labelled, sending it back and waiting three weeks for a new set, deciding to go with Mojave anyway and re-installing the whole thing I can officially say-
I have completed the build and it is unbelievable.
@CaseySJ, I followed your guide word for word and everything runs great. Still some issues to figure out, but the main thing for me was the video driver (that works 100%) and the stability (which until now is amazing). Thanks for the guide and for your help and advice!