Someone else said the wiring is the same on the DVD-ROM drive between the two different models (03-05, 06-07). I am not sure why you would need a new head unit since none of the buttons have changed and the screen is the same. I have never tested it.
Now, your other problem is that you bought a Hybrid Accord. The electronics in the Hybrid, especially the stereo, is wired completely different than the standard Accord. For example, you need a DVD-ROM drive from a Hybrid. You cannot use the DVD-ROM drive from the standard Accord because it won't fit in your lower pocket below the stereo. The Hybrid uses a different DVD-ROM drive model which is mounted in the lower pocket. Other Accords have the drive mounted in the trunk. You won't get any new features with the white DVD, other than the custom wiring that can be done to install a rear camera. Other than that, the only difference is an updated GUI with a brushed metal appearance instead of a flat gray appearance for the buttons, along with an updated font. So unless you plan on doing a rear camera, you would be wasting your money trying to find a DVD-ROM drive from an 06-07 Hybrid.