Some people will tell you you HAVE to get this or that, but in reality, you should be ok without other mods as long as you keep the drop around 1.5" or less. That being said, some people drop there's and the rear is way out of alignment. U could always do springs and dampers, then check your rear alignment and go from there. I've heard great things about watts link, but it might be overkill for a street stang...im interested to try it myself. Good Luck!
p.s....dont forget camber bolts
This guy Menance07 knows what he is talking about.
I HAD prolines on my mustang, car was too low. Only had 5.25" of clear from the ground to the roush chin spoiler. My rear was perfectly centered no need for any adjustment. Replaced with the Roush
suspension kit/bars/shocks/springs. Again, rear stayed put, no need for any adjustment. Your wasting your money with an adjustable
panhard, unless you do something wrong, remove the whole axle, or, drop it in the weeds.
Yours is a street car, you say, there are so many
suspension things out there like kids in a candy shop. Sure everything out there works, but maybe not on a street driven car. I have never driven a watts link car, but I would definately try to before I forked over that kind of money to see if it is worth it to you. I don't think that is something you'd see any gains on with street driving. kind of like adjustable
LCA's, unless you drag race each weekend, really no need on the street. The list goes on.
For me, I wanted well engineered stuff that works good on the street. For me that's the whole roush
suspension kit which is wonderful, and the GT 500
LCA's.
I would think (although I have never driven one) that the Ford Racing kit will yield similar results to the Roush kit.
The biggest change to handling and ride you will see is changing the springs. If you are on a budget just change the springs and the rear sway bar (if you can swing it). Everything else is minor in it's result (on the street). And dont forget the camber bolts and an alignment, unless you want to wear your stuff out and buy new tires. With 20's I woul not go lower than 1" or 1.25".
just my .04 worth