jonathan, my car went 50k before anything happened. Ben's RS6 is still okay. So while DRC is a concern, it's not like every single car that rolled off the line has this problem. I think you'll be okay, I mean, having that check up done at the dealership will be important but please do make sure that your dealership put an RS tech on the inspection and not just some random snot nose technician. I would also mention the DRC specifically. It wouldn't be that big a deal since they are already pulling the wheels off to install your new tires.
The alternative to the DRC is H&R (as far as I can determine, unavailable in the US), Stasis (generally good reception but complaints of squeaking), and Bilstein (also squeaking and some other problems), and the KW V3.
One note of caution, and I mentioned this on Richard's thread too, is that with these aftermarket suspension, the car will be tighter and the ride stiffer. My dad already doesn't like to ride in my car with the DRC and stock 18". Now that I will have KW, Hotchkis, and 20", he will probably never ride in my car again. I don't know how much of a concern this is with kids.