Sounds like an awesome project.
My sense is that you can't have BOTH optimal viewing height for your display AND optimal listening height for your center channel in that scenario.
That is, I've heard that you want your eye-level to be about 1/3 up from the bottom of the screen. I've also heard that you want your tweeters at ear height. Unless your ears are very significantly lower than your eyeballs, something's got to give.
Personally, I think it would look best and make the right compromise to have the display where it is "supposed to be" and then just put the speaker directly below it (basically, the very top of the credenza).
I'm very interested in your project, as I think combining the VP180 in-cabinet into a TV stand makes a whole lot of sense.
