[Current Setup] : HD600 -> HT Omega Striker 7.1

[Budget]           : $300-500

[Desired Sound]: Neutral ... allows for lower end frequencies but nothing that overpowers one freq over another

[Listening]        : %50 Games , %40 Music , %10 Movies. Multiple genres of music - no favorites.

I've been looking to upgrade. I have had my HD600s for about a two years. In that time I purchased a PS3 and M-Audio AV40s. I sold the AV40s - I really didn't like the sound that they were putting out. I was looking to upgrade to a better 2.0 system but feel that I would have better luck upgrading my headphone setup. I feel it's an easier task to do - I don't have to worry about room acoustics , I have less wires to worry about and less power usage. 

What I'm looking for is something that will last me for a long time. A great bang for my buck system that doesn't hold anything back. I'm all in. If I have to pay for it I'm willing but $500 (including shipping) is my threshold. I have a few questions though :

1. I want to connect my PS3. How would I go about doing this? When I tried to connect it to my soundcard I only received digital              

    noise/static when I started a game and so I had to connect the PS3 audio with the RCA input.

2. Should I be looking at a DAC , AMP , both? Is it even worth looking into upgrading my soundcard...or should I forget about that 

    entirely and go with an external?

3. Does the size of the connection matter? As in will a 3.5mm sound any different than a 1/4"?

I don't know what else to include at the moment. I would just like some help deciding where to go on this.

Thank You.

Thank you for the suggestion. That is above my budget but I will still give it consideration if it comes down to it. I'll also see about those Denon / Teac amps.

I'm becoming interested in the NuForce Icon HDP. It's right below my threshold and is described as something that fits my needs perfectly - great bang for your buck , dac / amp / preamp (!) and (while I'm not sure if it would of made a difference) a 1/4" headphone jack. It's all black and is of sturdy construction.

Is this worth it? I don't plan to upgrade after I do find what I'm looking for...at least for a long time.

Also...how exactly are the products reviews on the site? With the list and ratings it doesn't have a link to a review from this site or any others. Is it by user or popularity? I would like to know before using the lists as a resource.

When I do get a DAC / AMP is the soundcard in my computer really necessary anymore? I have an optical out through the motherboard but I will be using the USB connection since I want to hook up my PS3. 

I am also looking at the Maverick. I've reconsidered my budget and the Maverick looks a lot nicer and has more connections. It also allows me to "upgrade" the sound with different tubes.

In the end I bought the Maverick with the NOS amp. It has plenty of connections and can be hooked up to an amp if I feel I want to get back into listening with speakers , but for now I'm all for headphones. It will allow me to use my PS3 and PC and it has a nice selection dial. It is upgradeable as well. As long as it works with no problems with my PS3 I'm pretty sure I will be fine. I wanted something that would allow for multiple connections and is of decent quality and the D1 is it.