AMP/DAC for Denon AH-D2000?

I know, another thread about an AMP/DAC fro the Denon AH-D2000's. Thing is, I have some questions that weren't answered elsewhere.

Before I jump in with my questions and requests, this is the setup anything I purchase will be going in to. Basically, they are mostly used while I'm sitting at my desk, working on my iMac. My iTunes library has a very large portion of lossless audio and the vast majority of what isn't lossless is 256 Kbps VBR or better. I'm working on replacing/upgrading anything that's not lossless, starting with my favorite albums.

Now, I keep hearing that I might benefit from a good AMP and DAC and to that end I have a few questions:

1. Do I really need a DAC, considering my setup and usage? Or, alternatively, is there a software-solution I'm unaware of?

2. In terms of an AMP, is it possible to get something that could drive my headphones as well ask my desktop speakers? They're nothing special, just some Acoustic Energy Aego M's. I'm jus thinking my life might be easier if I can have them in one device and switch between the two.

Whatever AMP/DAC I get, it's going to be sitting on my desk (or strapped to the underside of it) so this doesn't need to be portable. USB-powered or self-powered, whichever is better. Ideally, I'd like to keep the price around or below $400 but I could be convinced to go higher if there's a good reason.

If the answer is I don't need a DAC or if there's a good stand-alone DAC I should get, what do people think of the Schiit Asgard? I've heard some good things about it and am rather curious. I know I can't have both my speakers and my headphone plugged in at the same time, but I can always swap cables as necessary.

I've heard some pretty good things about the Schiit Asgard but one thing I am hearing is that you can get a little noise on the low-end now. I was considering a Maverick AMP and DAC as together they hit around $400 but I've heard some mixed things there on the forum.

One question for everyone is it better for me to get a DAC or AMP first if I had to choose? For example, I might get an AMP or DAC first and then wait a month or two before I get the other one, which would allow me to spend a bit more total.

What do you guys think?

No advice at all?

The Nuforce Icon 2 would almost fit the bill perfectly but one issue that concerns me is it says frequency response is 20 –20,000 Hz where my headphones are 5 – 45,000 Hz. Now, I know that's supposedly above and below what's usually in the audible spectrum but might it be worth it to spend a bit more and get an AMP/DAC that can output closer to my headphones capabilities?

Or is it kind of just fluff?

Thanks for the advice.

Ah, see, didn't know that. Thanks for the heads up there. Think the Nuforce Icon 2 is the direction I'm going to be going. Seeing as it's small, within my price range and does everything I want.

Plus, it seems to be extremely popular on Head-Fi.

Any reason for the Red over the Green or White? As I said this is going to be coming from my iMac as a source so a DAC makes a lot of sense.

They're not big at all and they are self-powered.

http://www.acoustic-energy.co.uk/Default.aspx?pagename=Aego-M-loudspeaker

My real concern with the Red is that if I go that direction I still have to find a DAC.

Croozer, what are you using for your setup? Just an E7/E9?