AT&T HTC One - Sim Unlocked vs Unlocked and how to change the ROM to international ROM

[Reza Atabaki]

Hi guys,

I have an AT&T HTC one that is SIM Unlocked. I was wondering if there is a way that I can change the AT&T ROM of my phone to an international version (is there a US version but with no carrier lock?).
I don't want my international version to be rooted (just stock ROM). Also, I would prefer if it is the ROM with Sense 5 and not the google play edition.

It would be amazing if you could let me know.
Thanks in advance!