I didn't do a full on write up, but I talked about when I did this mod on my truck years ago. I don't have a part number for the clock spring, but the obvious difference between the DIC and non DIC versions are the 4 connectors for the buttons, which all have different pin configurations, so they can only be used on the proper button, and not swapped.
Once you get the clock spring and wheel installed, there will be 4 wires that need to be run to the cluster. In the cluster's plug there will be 4 open slots, together on the end. What I did for that, was buy a GM radio harness off Ebay for a few $$$ (was too lazy to scavenge one from a junker) and then steal the 4 wires/pins that were the same as the ones in the wiring diagram for the DIC functions. If you haven't already, get the service manuals from
@Mooseman 's thread, and you can find the pin assignments and wire colors in the wiring diagram file.
For the audio control, are you stock, or aftermarket? If you're stock, the truck's harness that the clock spring plugs into won't have the connecting wire for the data bus. In addition to that, your BCM won't be programmed for it. If you're aftermarket, as I am, then you'll need an adapter harness.
Depending on the model, you'll need to connect one of the wires from the clock spring to it. Some use the data bus signal, others read resistance that varies depending on which button is pressed.
Hope that helps some.