Not to sound insensitive. But soon you won't be able to buy any phone then. 3.5mm headphone jacks are outdated technology. I give it no more than 5 years until all 3.5mm jacks are removed from devices. There are so many better ways to listen to movies and audio compared to 3.5mm. Even USB headphones provide better sound quality. There are two reasons why I see Apple is doing away with it. 1)Waterproofing. 2) For a better audio experience.
You don't get better Audio experience and you can get lighting headphone now, without remove 3.5mm.
I doubt DAC on earbud will be any better than one comes with iPhone.
And you don't need remove 3.5mm to get waterproof. My sub 200 dollar Moto G is water proof and it has 3.5mm