Best high-end headphones with noice cancellation ...

Actually, this would be my first ANC - in case I go for that - I am used B&W P7 wired without ANC 

I’m not a huge Sony fan, but I have to say at around the $300 price level I’d go with the Sony WH-1000XM4 for it’s all-around solid performance. That said, I just bought my wife a pair of Sennheiser PXC 550-ll for $200 for Christmas that seem pretty comparable but not quite as good noise cancelling as the Sony. I’ll report back on sound quality when I get to hear them. Won’t buy Bose. Hope this helps, and best of luck.

One last thought I’m not quite sure about, but the Senns offer a wired connection that allows for lossless quality, and if you can stick a DAC or DAC/Amp in there (like an Audioquest Dragonfly Red) so much the better.  This would push me toward the PXC 550-ll for the potentially higher sound quality if it’s valid. 

Yeah, also looked at the Sennheiser ... was told thought that the sound is quite metalic ... 

With respect to traveling, I have had several pairs of in ear IEMs and also active noise cancelling headphones including Sennheiser and Bose for long haul flights, working, listening to music and / or watching movies.
I loved a pair of JH Audio IEMs which were custom made and wonderfully comfortable.  I get, however, a certain claustrophobia with even the best and most comfortable IEMs that I do not get with active noise cancelling headphones.
Both types would be good.