There's plenty out here...
2010-2013 Mustang Control Arms at AmericanMuscle.com - Free Shipping!
I've been looking at them myself, collecting a few parts at a time to do a whole new suspension setup on my 2011. So far I've got the Shelby fully adjustable lower control arms. Looking to get the LCA relocation brackets, upper control arm, and UCA bracket this weeek...so i've been searching too.
2011 Grabber Blue GT California Special, 3.73 Gears, 6-Speed Manual, Steeda CAI, Steeda 93 tune, aluminum driveshaft (The Driveshaft Shop Co.), MGW shifter, Roush axle-back exhaust, Roush Side Rocker Panel Splitters, Ford Racing BOSS 302 front splitter, sound-tube delete, painted plug covers, JLT oil separator. Shelby transmission scoop & powder-coated trunk brace & many more items...