I think you're looking for an audiophile-grade soundcard rather than an audio interface. I'd recommend the Asus Xonar Essence STX for that. It has a great headphone amp so you can plug your Sony headphones in. For speakers you'd need a hi-fi amp and speakers though. I don't think audio interfaces will really give you audiophile sound as I'd imagine they would favour revealing the sound over flattering it.
I'm not familiar with hifi amp. Is it ok if get xonar stx and connect it say to Sony ht ct80 soundbar or yamaha yas 207 soundbar? Can it encode and decode all the dolby and dts conversion