Check out Griggs Racing Products.. I have used their stuff on the early Mustangs and it works really well. It also uses the late model brakes and steering components, so it leaves things open for alot of different brake choices. And you don't have to have the factory shock towers to use their stuff. They also make a K-member the is ready to accept a 4.6...
http://griggsracing.com/
and check out their gallery
http://picasaweb.google.com/griggsracing