just to update and thank people in this thread for their time and help, the issue i had (not getting as far as the installer screen) was drivers.... solved here thanks to Rampage Dev. I probably have more to solve but making progress finally.
updated fine... only broke audio.
Replaced AppleHDA.kext. Restart/repair permissions, delete com.apple.kext.caches folder (I always forget to delete that) restart. Audio working.
Update: I'm getting KP's on initial boot up... dose not happen every time and after a hard shutdown and re-boot it's fine. Will try and take a picture next time it happens.