Need some help here, for planning purposes.

In the process of putting together a 981 order, I went yesterday and listened to the Bose audio....ugh. I expected it to at least be decent, but frankly, I don't know how anyone can take it seriously - and definitely not at the Porsche price. The $200 Kenwood I put in my daughter's minivan sounds a LOT better...and yes, I'm being dead serious. I'm not about to plunk down $6K for the Burmester, so I need a better option.

I assume that I need CDR Plus to get the amp and speaker wiring in place, speaker locations prepped, and USB connection in place, right?

So, I have a few questions.

1) How different is the CDR Plus from the Bose? Has anyone done a back-to-back to give comparison info? The Bose has tremendous response gaps - is the CDR Plus actually worse than that?
2) Do the Bose and Burmester upgrades come with a different head unit, or are they just amp/speaker upgrades?
3) How difficult is it to swap the audio system out in the Cayman S? Any problems integrating with the rest of the electronics? Can the USB and audio ports be connected to an aftermarket unit easily?
4) Any good sources for wiring harness kits, etc.? I've seen kits for the 987, but not the 981.

Thanks in advance.