Headphone amp and headphones... ?

There's a world of options out there in that price range and certainly some very good cans in the $1K range. The synergy between cans and amp is paramount and you should probably pick your amp to suit the headphones you choose. There is a VERY intimate connection to the kind of sound signature the headphones will yield, so screwing that up will mean the difference between potentially profound enjoyment, to flipping the entire investment when you discover you can only listen for about ten minutes before developing a headache because the cans you chose don't pair well with the amp and or just don't have a sound signature that suits your preferences. Headphones in that bracket can sound entirely different from each other and may suit different types of music better by design. I use the best all-around performer I've found in that price range; the Audeze LCD-2's. Other obvious candidates would include the HD-800's already mentioned, which are soundstaging champions but have a bit more of an airy sound to them, with a high-frequency spike that can really annoy some folks. Beyer T1's are also very popular, and Grado PS1000's are yet another in that range. Stax puts you into a different price bracket and are best suited by their own amps (or a more powerful amp in general) - they also have a unique sound presentation and signature and are also champions of soundstaging. You can find way more than you ever thought you'd want to know about this stuff on the headphone forums like Head-fi.org. Listening to headphones and listening to speakers are entirely different ways of experiencing music. You might also find you like one much better than the other. Have fun!

Headphones, like speakers, are a very subjective, individual type decision. If you can, go to some dealers that have headphones and try them out and see what you like. It's the only way.

I've said it before, let me say it again. Buy a used pair of Stax electrostatics with it's dedicated driver unit. I
heartily recommend the tube driver units. For $1500 you can
find a pair on Audiogon. You will never regret it. The Stax phones create an ambient space and it sounds like you are there. Avoid the magazine hype that the dynamic phones
can sound just as good-they can't. No, I'm not selling a pair, I'm just trying to save you a lot of trial and error.

Stax certainly have a unique sound, but they are definitely not for everyone. You should certainly listen before you buy if possible. I agree that headphones can be very subjective and also add very distinctive from each other. The only problem suggesting dealers is that there are not many who put any kind of emphasis on headphones at all. Dealers like 32 Ohm in Portland are the exception to the rule, but I can't say I know any other (brick and mortar dealer) like them. You might check to see if there are any headphone meets in your area. Head-Fi has a "meet" section of the forums where meets are listed as threads, and or you could inquire about meets in your area. You might be able to hear some very thoughtfully assembled systems at a meet and narrow down some of your options further.

wish I still had my old Stax headphones... Grado's have nice tonal color but no where near the transparency of electrostatics. But oh how electrostatics will drill your ears if you don't have a sweet amp to drive them.