Have a new 012 A5 Cab Quattro and want to upgrade the sway bars. The OE rear is 19.7mm and there is a 21.6mm available..The front is 27mm ,as best I can measure,but there don't seem to be any upgrades available. I looked at S4 options as well and no larger bar is listed..
Any input,,thoughts,,suggetsions would be appreciated.

That's probably all you're going to find for now - that car is a new enough generation/design that the aftermarket hasn't had long to work with it. You could check with the dealer about an upgrade from the RS4/RS5 and see if it's compatible. Bring money though...