Would the FiiO E11 be good enough for these?

  Looking at those I'd say that the Ultrasone - PRO 750 Headphones appeal to me most.   I think it will have to be either these or beats (as they're the only ones I'm able to test before buying  )

After reading reviews, posts etc I'm at a loss really, my mind seems to change with each article I read...so...   I'm looking for recommendations please as I have around $300-$400 to spend (saved up enough allowance from the wife  ), so this could also include an AMP if necessary?   I...