Installing touchscreen dvd, navi, usb

Hi all,

Im new here and i'm trying to install this. I have not clear where to power it, And I have a couple of question:

1. Can do this from original (symphony radio) stereo connecting directly into power wires of radio?

2. Using fuse box on the right (passenger side)?

In both case please give some instructions how can do this.

I have audi a4 b8 8k (2008) with radio symphony.