Consider going with either Maximum Motorsports or Griggs Racing suspension components. Both of these companies make top notch Mustang aftermarket suspension systems and are highly regarded within the Mustang community. When it comes to performance mustang suspensions, these guys are the best.
Before making any decision, contact both companies and tell them what you are looking to do. Let them work with you to determine the best setup and upgrade path for your application, timeframe and price range. Make a decision which one to go with and stick with it. Suspension components will work best when they are designed to work together as a package/total solution. Both of these companies offer well matched racing suspensions that can be purchased and installed in stages to meet your budget and level of performance desired.
Buying the right parts the first time will save you money in the long run as well as give you a solid foundation for future upgrades.
I went with Maximum Motorsports for both my 1989 and 1992 Mustangs since their suspension system best suited both my applications. I can speak first hand of the quality, workmanship and functionality of their components. Their service and support is also outstanding. I understand Griggs products and service is also of the same caliper. Here are the links to their websites if you would like more information concerning their products:
www.maximummotorsports.com www.griggsracing.com
Hope this is of some help and Good Luck with your decision.
autocrossing mustangs 
