What NA firmware can I flash onto my G920I?

Hey guys. I'm visiting India from NYC and bought a Galaxy S6 here. There are a lot of region specific things on this firmware that I do not like. For example, when I add new phone numbers, the automatic formatting of (xxx) xxx-xxx does not happen. Numbers just save as xxxxxxxxx and I have to manually add the formatting. This is just one of the many things that are bugging me. I want to flash an NA or equivalent firmware on my phone and was wondering what the most optimal firmware would be to use? Should I use a carrier branded firmware from T-Mobile or something? Does NA have a non branded firmware at all?

Thanks so much in advance!