Confirmed with the dealer that the two part numbers are 23224747 for the main dash and 23224733 for the extension, I don't have a center speaker and have the black ebony interior.
Prices I've seen for each online are around $450-500 for the main dash and $275-350 for the extension excluding shipping. Pricing from a dealer is $660 for the dash and $420 for the extension. I've got a very good relationship with the service department at my local Cadillac dealer and they are going to see what they can do on pricing for the two parts as they understand the dash issue but I am not the original owner to either vehicle.
From a warranty perspective, if I get the part through the dealer and the dash cracks (Second generation should not) its covered and I exchange the part at the dealer. The extension isn't as important as the dash as it comes in a giant box by freight as others have mentioned whereas it can ship direct to the dealer.
I will need to take pictures for my own sanity when the dash comes out so that I can get the thing back in, I will absolutely share when finished.
My goal is to get the dash purchased this week and with shipping get in my hands by the end of next or the week of 8/15, that should allow for me to complete the actual conversion on the 20th or the week of the 27th.
Holding up the dash swap is my selection of a new Nav unit, I want to swap everything at once as I need to route the GPS antenna under the dash for the new head unit.
I need to get it completed prior to 9/10 as that is my last full weekend prior to heading back to Saturday grad school.