Debloated stock ROM that is up-to-date and auto updates?

Hi all, sorry if this is a bit of a **** first post but XDA has been real good to me in the past.... did all sorts of cool stuff with my old S3 based on posts here so thanks heaps for all of that. But I've done a bunch of searching and can't find anything about this question...

I got an S6 yesterday, lost the S3 skiing so my insurance company got me a new phone (score :D). Had CM on the old one but battery life was ****, before that I had a ROM the name of which I can't remember but it was bare-bones android, no frills, super fast and battery life was great.

Anyways I'm after a de-bloated stock rom for the S6 that is kept up to date and will auto-update... basically I want a stock standard phone but without all the junk that Samsung threw in. And if it has to go back for warranty, it needs to look legit.

I found an article about a stock T-Mobile ROM with no bloatware (can't link since it's my first post but Googling "samsung s6 debloated factory rom" brings it up as about the fifth result) but it's a few months old and I have no idea if it is still up to date... I also don't know if this is really a 'stock' ROM or what...

Is it possible for me to install a factory ROM that won't void my warranty and will give me a nice clean install of 5.1.1 or whatever the current version is, plus will automatically install available updates?

Thanks heaps.