B & W P5's or SHURE SE535/SE425...

Folks -

 I am investing in a pair of headphones purely because I never get enough time at home for the silence I need to enjoy music.  So I am torn between in-ear canals or closed headphones - to keep out the noise whilst maintaining sound quality.

I have nailed it down to the SHURE SE425 - or SE 535 against the B & W P5's...and around 300 pounds is my limit.

I should say that I am also looking for a good quality headphone amp without stretching beyond 400 pounds. But that will come later depending on the cans I buy...

Equipment - you may be disappointed that I bought the ipod classic - but the memory of 160 GB is hard to argue with - if I want a large walking library of sound...though indeed, I am aware that the sounds from these things are far from adequate. That is why I wanted to do good on the next two components...

Keen to hear your opinions....

Listening habits - alot of classical music, All kinds of jazz especially fusion, also R & B, and bands like coldplay, muse etc...

please advice....