[somniphobiac]

Ok so I have a quandary for you to ponder. The basics are this; I have a pair of ath m50 that need repair (broken cable and such). Subsequently I have decided to get a new set of headphones, an upgrade of some type. I edit and mix for films, sometimes professionally sometimes not. I love alt rock punk  indie and rap etc. In my research the brand that stood out the most (for comfort, build, quality and sound) were the Beyerdynamics. Namely the dt 880 ohm (nice, flat, and open, would be great to mix with) and the dt 770 250ohm (a bit too much bass, wish they were flatter,  fun to listen to), both of which I tried. Very different cans but both sounded great to my ears even just running off an iPhone though the volume was maxed (the store didn't have a proper amp to demo them with). I have 350 to spend (will look used etc to make ends meet)  What should I do? Fix the m50s for mobile use and get the dt 880 with an amp? Is the 600 ohm version worth getting even if it means spending more on the amp? Or just get the dt 770 with a better amp? What amp? I listen to music on my laptop 80%  (read: portability is important) of the time the rest is my iphone. So a DAC would be great. Or should I scrap all this and look at something else? Anyways I am done giving myself headaches and thought I would share the burden. 
Thanks in advance.

Ps: sorry for spelling errors (written on iPhone)