I'm a Head-Fier! I don't know much about AudioTechnica, but I Googled the ATH-AD7 and only got 12,000 results, almost all of them in some Asian language. Just curious, why are you trading them?
My current audio equipment is...limited. I've got Sennheiser HD497s and an Audigy 2.
I just ordered some Koss KSC75s, them and the KSC35s (same drivers, KSC75s are supposed to be more comfortable) have gotten a lot of good marks over at Head-Fi. For about $22 shipped, they're the best bang for your buck, period. I'm told they're pretty balanced sounding. While not nearly as detailed or precise as other sub $100 cans but a very "fun" sound.
I'm going to build a PIMETA headphone amp soon, and probably upgrade my soundcard to either a Chaintech AV-710 or an E-MU 0404. Probably the 0404 because I can patch my Audigy 2 into it via SPDIF and still get EAX in games without a total loss in quality (because the SPDIF output is raw and unamped). The amp will cost around 50 or 60 dollars...most of that is in the opamps and buffers. I'm using AD843 opamps, which are supposedly really awesome for about 8 dollars. And then the Burr-Brown buffers are like 6-7 dollars each and I need three of them. :/ Hopefully I can save a little by buying all my resistors and caps from Futurelec...DigiKey is a ripoff...until you hit the pricebreak and buy 10000 of each item. I might even mod my E-MU 0404 and replace some of the caps or opamps, I hear they make quite a difference.
For cans I'm looking at either the Grado SR225 or something from Beyerdynamic. I've heard awesome things about both of them and I'd like to give them a try. I should also see what dad's old HD414s sound like on an amp once I build it. I also haven't listened to them since he put the proper replacement pads on them, they probably sound a good bit more clear.
/rant
I believe Malus is a Head-Fier...or at least
Bassoon, n. A brazen instrument into which a fool blows out his brains.