I've also been thinking about a brake duct kit recently, will summarize my research so far.
First, I really like the air inlet configuration from this homemade kit that utilizes the factory undertray,
LINK. If I went this route I would eventually plan to get one of the front splitters that has air duct inlets built in.
Then I would agree with 4M that the Cantrell kit backing plates would be nice. Check out
ortho281's install here,
LINK, see post #123.
Regarding rubbing, both
jakob66 and
ortho281 had rubbing of some sort and installed the Turner Motorsports steering limiters which remedied the issue,
LINK, see post #230 and
LINK, see post #128.