Couldn't you go with the 250 if your going to be running an amp anyways and just use the e11 as your amp on the go?

I'm also very seriously looking into the 990's and much prefer the look and straight cable of the premium. I was leaning towards the 600 ohm impedence ones but get the impression that I would need a larger (more expensive) amp to drive them. Is that correct?

Would a combination of the e10 and M-stage be adequate to drive the DT 990s with 600 ohm impedence?

I like the looks and price of the Fiio e10. Going to look into that a little more. Those are all around the price range I expected. I'm mostly just listening to music and the gaming that I do do doesn't require great locational precesion. 

I am looking for a relativley affordable DAC (probably USB) for using my laptop as the source. I will be purchasing the M-Stage amp from Matrix and therefore won't need a DAC/amp combo. Portability isn't a huge issue either but I'm not opposed to something portable if it fits the bill and price...

I'm looking for a pair of full size over ear headphones. I am leaning towards open because they will be exclusivly used at my house in my dorm.   I would like to pick up the Matrix M-stage amp for them because there is currently what seems to be a very good deal for them on Massdrop. My...