Question [Q] How to root and change rom from touchwiz to official latest kitkat

Hello,
I have some questions about my s4.
Is it possible to flash a touchwiz version of gt-l9505 to an official kitkat rom (making it GP edition) and receive direct updates from google?
If yes, i would like to know a safe way on how to do it (because the forum is a little chaotic and i am afraid to make a change on the device by my own). I would also like to know if there is a way to reflash to original touchwiz rom in case GPE does not comfort me, i d like to know if it will be some kind of backup or if the official touchwiz rom is able to be downloaded.
I will appreciate every efforts in helping me clear those question marks in my head.
Thank you very much.

Device info: Galaxy s4 GT-l9505
Version: I9505XXUFNC4
Unlocked
Unrooted + official rom