Why not try the Burson Audio Soloist? A review can be found here. I have always been pleased by the products put out by Burson Audio.
http://www.innerfidelity.com/content/burson-audio-soloist-headphone-amplifier
Keep in mind the unit does not have a DAC so if you need one you will have to order that as well. I suggest the the HeadRoom Micro DAC @ $320.
Total Cost:
Burson Audio Soloist @ $880
HeadRoom Mciro Amp @ $320
Various interconnects @ $100
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$1220 US
You will have a separate DAC, separate amp, and plenty of power to drive almost anything out there.
Micro Amp Page:
http://www.headphone.com/headphone-amps/headroom-micro-dac.php