Well, if you are only going to listen through headphones, bearing in mind that you ought to restart with WAV encoding on your iPod to arrive at something like 'audiophile' sound, i can heartily recommend the PXC 300 by Sennheiser, if you want noise reduction, or simply Grado 60's, both of which I have and both of which work excellently straight off the iPod. There are plenty of headphone amps around - on my big rig I use a Creek, but I cannot say I know much about headphone amps in general.
As for cabling etc, if you run everything off the pod, you need no mains other than to your computer! In Switzerland, on the big Naim rig, I have installed a dedicated spur from the fuse box, as it is a new apartment, and that seems to have greatly improved things.