[Q] Make a Stock Backup of Newly Purchased M9 topic

I am very close to pulling the trigger on buying an M9. I have searched and searched both on here and with google on how to do a stock backup of a newly purchased M9, but everything posted is how to recover from a downloaded image.

Does anyone know a link or can give me a nudge as to where to find out how to make a stock nandroid backup of a newly purchased M9? Is it even possible? I would like to take an image that does not have root and will allow me to revert back to my original stock image and get OTA updates.

I am new to the android scene in the sense of flashing roms and tinkering. I usually just use stock settings, but android it getting way too bloated and way too invasive, especially with permissions. I really would like to tinker with some custom roms and some root software that strips bloat and controls network access and the like.

I have read tons on twrp and cwm and how to root this phone. I have the general gist, but I have not seen anthing on making a nandroid backup after initial purchase.

Thank you, any help would be greatly appreciated.