Here's the radio image by itself:
radio-bullhead-m8994f-22.214.171.124.56.img (Google drive)
Since this is a vanilla android phone, the only real modification I wanted was to change the hosts file to block ads. Turns out you can do that without rooting your phone, but you DO need an unlocked bootloader.
After you're unlocked, you'll ne...
The Developer Edition is still on sale. Can't beat that for easy to root.
I can't tell you for sure, but it's certainly a possibility. Having a backup is always a good idea, but there is a flashable stock hosts file in the same thread as the ad blocking file.
Personally, I'll probably just flash the factory system.img ...
Another vote for size, and I would have preferred something a little smaller.