Can’t beat the Akg closed back but open sounding k550’s excellent headphones, although you would have to settle for mk2 version. Shure makes two nice options in the closed back 1540’s and open back 1840’s. Also, now discontinued Audioquest nighthawk and nightowls. AQ got out of the headphone business, but these two were highly regarded headphones. As for an Amp to drive them, I like the Graham Slee Novo or the solo. I’ve had those aforementioned AKG k550’s for years now, they are my go to headphone, comfortable and non fatiguing sound, with plenty of detail and sound like an open back, but no sound leakage whatsoever. I own the Graham slee novo headphone Amp and it drives just about anything. Not sure why people always mention a dac to go with headphones, as the dac I use, the Border Patrol dac, is used within the system for cd playback, connected to a Cyrus cdt. Unless you are just doing a desktop dedicated headphone only set up, then I guess you would need a dac, idk. When I need to listen to headphones, I use the Novo, as I can play all sources through it, as it is a daisy chain style Amp. It is unique In this respect. I can listen to my cd’s, turntable, cassettes, fm tuner, and streamed music through my Novo, all I have to do is change the source selector on my integrated amp.