Out of the ones listed (please also add other similarly priced ones that you think are suitable), which one would you go for?
Music I listen to pretty much has to have a guitar in it somewhere, although I do listen to Kanye West, Nujabes, Eminem and Jay Z among others now and again. Some of the artists I listen to include The Beatles, The Rolling Stones, The Arcade Fire, The Antlers, The Beach Boys, Bob Dylan, Bright Eyes, David Bowie, Sigur Ros, John Mayer, My Bloody Valentine, Slowdive, Led Zeppelin, The National, The Libertines, Pavement, Pink Floyd. I also listen to acoustic stuff, like Jack Johnson, Elliott Smith and Jason Mraz. There's plenty of other artists, but that should do. Blues and pop music should also be taken into account, but to a lesser extent.
I'm planning on powering one of these headphones with an O2 amp. I was considering one manufactured by FiiO, but keep on hearing how the O2 is better. If anyone has any other recommendations for £100, however, then I'm all ears.