Yes. They should firm up the ride well enough. But if I had to do it again, I would get the sports.

 

We tried engineering a full range of components for the BMW M3 and surprisingly was not able to improve the vehicle too much to the point worth bragging about. The M3 engineers really did a good job with the chassis stiffening and bushings. That being said, our bushings kit made the average 3 series handle like (if not better than) the M3.

The Mustang needs some basic components to button up the ride. I'd say sway bars are still the best bang for your buck! Once you've gotten sways on, feel what you don't like about the car and research before you just start diagnosing based off of how others drive but I will say the bushings leave allot to be desired.

the entire process can get pretty pricey but to answer your question I'd say:
Sway Bars
Upgraded tires
Coilover or Spring/shock
Watts Link