Good luck on looking for a clan :) I am also a Free Agent at the moment and the only clan really looking for members are scrub clans or the type of clans that disband after 1 loss :( Are you looking for a clan on GB or NxG or both?
Any Linkin Park song that goes hard, Mostly rock songs are good for montages but I've heard a few good rap songs that would go good with a cod4 montage.