Best currently avaialble PCI sound card for stereo music (under $300)

Like many, I'm putting together a PC as a high quality source component. I would like to keep the analog audio stage in the same "box", and am hoping to use an internal sound card instead of an external DAC. I only have PCI available.

So I'm hoping for some help in idnetifying the PCI sound card that provides the best sound quality for music listening. I know that there are many threads with different flavors of this question throughout head-fi. But none completely address what I'm trying to answer.

In order to narrow things down, here are the criteria to my question:
1. I'm concerned about sound quality as a line level source. I don't want to confuse the discussion with a requirement that it drive headphones directly (though a built in headphone amp would be a bonus).
2. The music played will be a mix of WAV, FLAC and Apple lossless. No MP3's or lossy compression.
3. It will end up driving a reavealing amp/headphone combo, and eventually a nearfield system (possibly a pair of audioengine's or maybe later a SET amp with monitors)
4. I don't mind/care if it can support surround sound modes, games, headphones, etc. but line level stereo sound quality is the most important aspect.

Here's the list of card's I've come up with.
HT Oemga Claro Halo
Asus Xonar D2
Audiotrak Prodigy HD2

Ive pretty much ruled out anythung X-Fi. Not sure if I'm missing anything else. I've read good things about the M0

All offer a high quality DAC. All are CMedia based. All claim to use high quality components. So of the three, which offers the best overall sound quality?

-Everyone who tries the Claro Halo seems to like it.
-The Prodigy HD2 is not as well known, but has a similar architechture to Claro Halo (differntial signal from the DAC, 2 stage replacable outpu buffers.
-RMAA measurements seem to give the Asus Xonar the edge despite the fact that the card is indented for surround applications. I know the least about this card's architecture and potential.

Another spin on this would also be to discuss "bang for the buck". The selling price of the list I provided ranges be over $100.

Any an all input is welcome and appreciated. Let the debate begin....

Mr. Duck,

Thanks for your input. I respect your opinion, but would really like to keep the discussion grounded to evaluating/rating/discussing PCI sound cards.

The "sound card vs. external DAC" is a complex one. I find that these threads are more informative is they stay grounded.

Are the Asus drivers really that bad? I'm planing on using this in an Atom based system inteded as a music server, so I'm hoping for a driver with low CPU overhead. Will the ASUS cards be a problem?

Also, leepery, is the Essence ST/STX better than the Claro Halo?

What about the Xonar D2. That can be had for about $100 these days. Should I even consider that one?

When you guys are recommending the Asus Xonar, are you referring to any of the models. The STX seems to be the best, and I know that the ST is coming out soon, but the is the D2 a recommended card as well?