Okay, it does certainly sound though it's the GPU or its driver causing the problem. It it boots that far and then sticks it is not changing over to the GPU drivers correctly. If it boots to UniBeast it is running without acceleration. Unless you have faulty hardware that proves that your system is ok just not configured.
So are you installing Sierra or High Sierra?
Try this -
Insert the UniBeast stick.
Check which Disk ID it is by running DiskUtil
Using "EFI Mounter v3" from the downloads section, select the correct Disk ID when it shows you the two and then copy UniBeast's config.plist to your desktop.
Unmount UniBeast.
Mount the EFI partition of your main hard drive.
Navigate to the EFI/CLOVER folder and rename the config there to something like config.old etc.
Copy UniBeast's config.plist into place in your hard drive EFI/CLOVER folder.
Reboot and then install the Nvidia drivers again. Use the -x command-line if you need to but I don't think you will.
Reboot and see how that looks and report back.