Rear Suspension

i think your talking about the Quad shocks.Thats all i have to say about it not gonna say wether you need them or not.

or take that money and buy a nice set of lower control arms, like MM's pieces

Put the quad shocks back on if you took them off or don’t have them installed.

The quad shocks are a roll of the dice. No matter what the combination of tires, control arms and shocks, some cars will wheel hop without quad shocks and some won't. There are so many variables in 28-13 year old cars with wear, misalignment and combinations of suspension components and tires that one unchanging answer won't work for everyone.

I personally would install them, and make sure they are in good shape. I do know this, that Ford is cheap. If they could have made changes in some simple component like bushings or control arm construction and saved $20, they would have done it. Multiply $20 times all the Fox body Mustangs ever made and you would be almost as rich as Donald Trump. That's a lot of $$$, and good incentive to engineer something to do away with the quad shocks.