I think when he is a little older it would be easier to tell for sure. I am going to conclude Nosy Be due to the coloration being intense teal/blue. I also find that the head of the Nosy Be seems to be long, narrow and pointy. But ask my wife, I have been wrong before!
I don't think blue ambanja, I haven't seen the blue and white stripes in the gular area like that, not in nosy be either. Red and blue, not blue and white. Makes me think nosy faly.
You guys better quit talking about your wives or you'll be getting punched in the nosy!
I would lean towards Nosy Be / Faly cross. Too much white for a Nosy Be, and no red rain to be a Faly. Reminds me of the "Faly/Be" crosses that come in from imports. Just because it looks like "X" locale, doesn't mean it is unfortunately. A lot of crosses can actually look like pure locales. This is why I always recommend going to a legitimate breeder if you care what locale you are getting. Don't buy 2nd hand or from Importers who are just going off what they are told.
He looks very nice though! And if locale truly doesn't matter, you have a stunner.