i just checked if you go on stangsuspension.com click 05-07 mustangs then click suspension componants. the first 2 things a bilstein shocks and struts.
This is a little spendy, but looks like it might cover all the bases. Stiffen up the suspension and give it the freedom to move without any binding issues.
As I am looking and researching for these kits, I have found only company that makes one specifically for the V6. The Eibach "Pro- System" kit from Summit Racing is probably in my future, but I need to do a little more looking around.
Yes I have the Eiback pro kit. It is good but you need to do more to improve the handling. I also added Steed front and rear sway bar kit with the upgrade end links. Also the strut tower brace makes a lot of difference (ESPECIALLY FOR ME AS I HAVE A CONVERTABLE)
You may be interested in this. Every year a British magazine called EVO hold a Performance Car Of The Year test. Basically they take a bunch of cars from the cheaper end of the market and pick the winners after a thorough grilling on track and through the Welsh mountains (that's Wales). A couple of years ago, the Top 3were the BMW M3 CS followed my the Roush Mustang followed by the 350Z. The Corvette C6 came 10th out of 10.
As I understand it, the Pony package is basically the V8 suspension which can be a bit soft. I have Tokico D-Specs (which I bought after reading an article about the Steeda Screaming Q which used them...) and I use the Roush springs and have kept the stock sway bars. We have runs here in the UK and the cars range from Japanese stuff right up to the new M5, Porsche GT2 and even a Murcielago. Mine does just fine in the handling department against all of them. At the end of the day, performance tends to be limited more by the road than the car.