I tried working this out here, but could only go so far because Nvidia's installer checks for an Nvidia gpu before finishing the install, and that's not what I have. But it does look like nouveau load in initrd is what's blocking you.
While I do "have a clue", I do not really *know* what I'm doing here, so back up /boot/initrd.gz and the entire directory /boot/initrd-tree before proceeding. Very likely you'll want to restore them. Leave the original copy of /boot/initrd-tree in place, because it's read by the mkinitrd command below. It's ok to leave the original /boot/initrd.gz in place as well.
Now edit the file /boot/initrd-tree/load_kernel_modules. Prefix a comment marker ("#", naturally) to the line
There shouldn't be a need to remove nouveau modules, etc.
Check those backups one more time. When satisfied, issue the command:
If lilo is your bootloader, run lilo so the new initrd.gz is loaded at boot. Grub shouldn't need this step.
Reboot. What should happen is that the vesa framebuffer will be used instead of nouveau, so your display will probably look different. Now see if nvidia installation will complete.
I thought about adding instruction for putting nvidia.ko in the initrd, but that would be making even more assumptions on my part. So please let us know how the initial driver install goes and the rest can be picked up from there.