I think I'll go for HTC one plus. But I heard that it have some battery issue. Motorola would be similar more or less. And, yes it is not difficult to make a phone country unlocked or evening it with country unlocked

Si ça peut t'aider, il y a un service pour facilité l'achat de produits aux USA. As-tu entendu parlé de From-US.com ?
A bon entendeur.

Go for OnePlus One.It offers Powerful cameras and HQ display.The device comes with 5.5 inches (Large) display,13 MP Primary camera and 3100 mAh, Li-Polymer bettery.The OnePlus One 64GB sports connectivity features such as 4G (specific brands), 3G, GLONASS, WiFi, USB port, GPS/AGPS, Bluetooth v4.0 with A2DP and NFC.Go for it.

One question back: why are you not considering the iPhone 6? are you dissatisfied with perfromance? Is it the price?

So, i´ve used iphone 4 for the last couple years and I´m changeing to android.

I´m going to buy it in the US but take it to Brazil, so i guess it needs to be unlocked.

I think these are the best options avaible for me:

Oneplus one
HTC one
Motorola Droid Turbo
moto X

Questions:
Can I find them unlocked?
Where to buy it?(I´ll be in texas)
Any particular phone you think is best?(among these or others)

Thank you very much!