The Best Audiophile Earphones headphones and Amp

Word to the wise...take it slow. I,too, have a pretty decent 2 channel system and thought that I'd like to enter into the headphone arena. I started by doing a little research on Head-fi.org and there's really quite a bit of information available. The Sennheiser 650's are a "good" pair of headphones and can be bought reasonably for around $500. A decent entry level headphone amp to drive them will run around $700 new. Start there and see how much you really like headphones. Sure you can buy a $1500 set of "cans" and spend 2 grand for a superior headphone amp and get a much better setup, but sometimes the journey getting there is better than the final destination. From your initial comments about your high-end hi-fi system, you probably built up your current system by steps so why not do the same with a headphone/headphone amp system because there will always be something better to move up to.