The best thing you can do is to audition as much stuff as possible.
The HD600 is really nice but I prefer the Grado RS-1. I don't like way the HD600 smoothes over all recordings good or bad. When the album has bite, I don't want a filtered out kind of distant rendition. You can get a very comfortable fit by bending the headband and tossing the earpads in the washing machine with some hair conditioner.
As for headphone amps, they range from $99 to $5000. Poor to astounding. I didn't really find anything to my liking until I broke the $700 barrier. Lower priced tube amps were seriously flawed in one way or the other.
The HD600 is really nice but I prefer the Grado RS-1. I don't like way the HD600 smoothes over all recordings good or bad. When the album has bite, I don't want a filtered out kind of distant rendition. You can get a very comfortable fit by bending the headband and tossing the earpads in the washing machine with some hair conditioner.
As for headphone amps, they range from $99 to $5000. Poor to astounding. I didn't really find anything to my liking until I broke the $700 barrier. Lower priced tube amps were seriously flawed in one way or the other.