you might want to try looking at a pair of canal phones for noise isolation. check out
www.etymotic.com or
www.shure.com for some of there products. i have a pair of the etymotic er6i and they are incredible with sound isolation when you get a good seal. on my way home from work i listen to them out of my ipod while my brother drives with the radio up and i cant hear any of it. they are pretty good sound quality also right out of the ipod. you can definately get better than the er6i. a word to the wise though, do not fall asleep with them on. i did that once and slept 2 hours late while my alarm was blairing.
-chris