Well, I ended up getting the HeadRoom Micro Amp and DAC separately. I went $300 over budget, but I'm really happy with it so far. I've only received the DAC (the amp arrives tomorrow), but it's made a huge improvement over both my sound card and my Icon Mobile. The clarity and imaging are significantly improved, and everything sounds just a bit warmer. Bass is more powerful, but no less controlled.
Ultimately, I looked around and nearly everything else was going to be a much more complicated ordering process -- I'm sure there are plenty of nice amps and DACs made by individuals and more obscure shops, but there's something to be said for the professionalism and ease-of-use that HeadRoom offers. Big enough to have things in stock ahead of time, take credit cards, and offer reasonable shipping rates, but small enough to take my calls during the ordering process and get back to my emails within minutes, often times. The quality of service was really great.
I'm very excited to hear what happens tomorrow when I can pair it with the Micro amp.
A quick question: do DACs have burn-in? I know amps do, and obviously headphones, so I sort of assumed that DACs also experience burn-in, but I'm not entirely sure.
I still have my Micro DAC/Amp combo, and it is the main DAC/Amp for my bedside rig which I feed from either an iRiver H140 via optical or a Sony D-EJ2000 portable CD via optical. I also often feed the Micro DAC into my modded Stax SR-001 in ear amp/phones. I used to alternate between the Micro Amp and Meier Headfive or Travagans Red with upgraded opamps for the bedside amp, but haven't used those others in a while.