There are. You just have to piece it together yourself.
I bought the Vorshlag backing plates for $170 +$20 shipping then ordered 10 ft of high temp 3" ducting from Summit Racing. All you really need is your own hose clamps and some large (15" minimum length) zip ties. Total cost to me is about $250, $80 less than the Ford Racing kit.
There have also been some issues with the hoses not fitting properly over the backing plates that Ford Racing supplies. The duct I bought slipped right over the openings on the Vorshlag plates.