Ahh, so having a pretty decent portable set up would be pretty important (though I'd just lug my computer with me, granted I could). Though I'd start with considering what you bring with you. A computer + DAC +Amp will probably be more satisfying, you can bring a much larger chunk with you. Unless you really only have like 10 songs of raw awesomeness. My dang iPod is 8GB and it's filled to the brim, pain.
(Excuse me for cruddy English if it happens. I always decide to go on head-fi when I'm dead tired. Genius.)
I wish I could bring my computer with me. Unfortunately, it is quite large and unportable, and all around a pain in the royal behind when flying. =P And my iPhone is 64 GB, so it can hold quite a bit of awesomeness (albeit, only MP3 and ALAC).