+1 amp first. If you're listening to mainly vocal/accoustic/lighter piano stuff, you might appreciate a DAC first, as the cans will still do the lighter stuff with great detail without too much juice, and the better representation from a good DAC might be better. But as soon as you want dynamic music, they're going to sound really flat without proper power, and no DAC will do for them what an amp will.
All comments say the Gilmore should be an excellent amp for them (hope to try one out myself soon, but already have something similar, so it's hard to justify).
That said, maybe get the cans first and have a listen before adding to the setup specifically to complement them. They're not to everyone's tastes. Properly powered, I don't think they're as bass light as people tend to say, but they are still very dry, and that does mean that the bass doesn't boom like it does with other phones. And the whole presentation is always very analytic and micro-detailed feeling.
Edited by PWilson - 7/11/10 at 7:54pm