Need help picking a Headphone amp.


I recently purchased a Westone 2 IE phone and I love the sound that comes out. I have become so hooked listening to it, that I know want to purchase a headphone and amp for my home system. I am looking to purchase the Sennheiser HD598.

I want a really good amp, but I don't want to spend more than $400. I am looking at the PS Audio GCHA, Headroom brand, and Project Box II. Can anyone help put me in the right direction?

Thanks,
matt00
Buy several as you should be able 30 day return. It is fun to compare and before the 30 days is up you should have winner.
Schiit Audio Valhalla @ $350 new is my entry for this thread. Great sounding and really sounds good with Sennheiser headphones. I have a pair of Sennheiser HD580s and the Valhalla handled them quite nicely. Just right on the bass and excellent in the midrange and treble.
I heard that Schiit Audio Valhalla does sound good with Sennheiser, but I was curious about Headroom. Thanks,