Doh sorry didn't fully read title. But i think some of my ideas my help.
No such thing as ota official Samsung android without touch wiz.
The best your going to do I guess is use Google Play Edition rom and do full unroot.
The other thing is maybe use aosp rom and full unroot or cyanogenmod and full unroot.
Anyway there are a few ideas for you.
Sent from my GT-I9505 using xda app-developers app
Update: 8th April 2014
Samsung Galaxy S4 👉😆😄Echoe rom v20😄😆👈
Still on old BMG4 Boobloader + FNBH Baseband.👍
HTC Desire HD
(Hboot 2.00.0029 AND S-OFF)
SVHD V 2.1.0
Retired HTC Legend