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  after some reading i have few options in mind , B&O H6 , B&W P7 , V-Moda M-100 and the new Beats Studio .

Haven't heard H6 but those others in my opinion get beaten by NAD Viso HP50 (based on sound quality alone) tho they might not suit you design wise (especially since P7 looks so good) and they don't fold... Still might be worth checking, they have somewhat neutral and balanced sound with great soundstage, bass is there but not overwhelming at all, so it should suit you based on your short description of what you want sound wise. Also they are low impedance and fairly sensitive so you should be able to drive them with any kind of smartphone/ipod you already have to pretty much full potential. They are ~300$