Very interesting thread, and a heck of a problem to solve on a message board, without real-life comparisons.
I agree with most everything that's been said, as strange as that may sound, given the diversity of views. Everyone who's posted has offered thoughtful information and sincere opinions, which, of course, leaves Taphil much better informed, but still struggling with his original question.
Well, let's see. I certainly understand the logic of jpelg's last post. Koss KSC-35 earclips do seem an almost perfect design match for the iPod. Much better than the earbuds that come with the iPod, and yet not so far above it in quality or size as to make an awkward odd couple kind of marriage. For $30, the KSC-35 is truly one of the best buys in the entire world-'o-heaphones.
On the other hand, Taphil, I can appreciate your wish for a higher-end solution to get the most out of these new technologies. So much of the American-dream-obsession around personal computers and consumer electronics is simply bogus pie-in-the-sky. In real life, most of this crap doesn't work half as elegantly or effectively as the advertising hype makes out.
The iTunes/iPod combination, however, is among the notable exceptions---software/hardware that is truly well-designed, effective, with elegant user-interfaces, and that makes life easier and more enjoyable. While I have nothing against those with the means and desire to go after audio perfection---filling whole rooms with ultra-expensive gear and insisting on only the most pristine source material---those solutions are unsuited to my temperament and limited budget. And yours as well, I presume.
I listen almost exclusively to mp3s these days---from the iTunes player of my Pismo Powerbook. My mp3s are either downloaded from the internet or ripped at 192K from my own CD collection.
I love having hundreds of hours of music instantly available on my laptop. With iTunes, making my own custom playlists is a snap, and the music I want to hear is instant-access, right from my desk. I am so relieved not having to hassle with all that organizing, searching through, and changing CDs, or buying some beaucoup-bucks 200-CD jukebox-changer.
The downside compromise, of course, is that mp3 compression is undeniably low-fi technology---I can indeed hear digital artifacts and compression drop-out on many cuts. I've recently begun experimenting with Orb Vorbis compression for the Mac, but I haven't yet decided whether it's worth the considerable investment of additional time.
I own both Senn HD580 and Alessandro MS-1 (equivalent to a Grado SR-125) cans, along with a beautiful little CHA47 amp I bought from erix, who built it. So my chain goes from mp3s in iTunes through the Powerbook soundcard to a Markertek interconnect to the CHA47 to the MS-1 to my ears. It may not be perfect, but it's damn good, and, more to the point, it makes me happy.
I can tell you that my CHA47 does NOT drive the Senn 580 to anything near its innate potential. I say this not because the Senn sounds bad (it doesn't---it sounds great), but rather because it's not significantly BETTER than the Alessandro. In fact, I prefer the MS-1. So I presume that the Senn would benefit by an upgrade from my $85 CHA47 to the next leg up at around $350 for a Corda Headamp-1, a Headroom Little, or an Antique Soundlabs MG Head.
Best of luck with whatever you decide.
--Bill