Oneplus One.
Meets every requirement you listed above and more. The phone is so powerful that I have it encrypted, and ATT doesn't even know what type of phone I'm running on their system. None of that built in NSA register stuff you find with Apple.
Home - OnePlus.net
Also you get everything that a 6 offers at a 1/3 of the price. The trick is being able to get one. Best bet is to get an invite off Ebay then order.