roush or ford suspension

If you want to autocross, I wouldn't choose either one. I had the Roush set up and I have replaced the shocks already and would replace the springs and the sway bars if I had the money. I replaced my Roush shocks with Koni Sports, aka "yellows" and I like them a lot better, they are adjustable which is a good feature. They go well with Steeda Sport springs and Strano adjustable sway bars. I would not worry about who has better instructions, none of them are hard to install, and if you have directions for one kit you can use it to install pretty much any of them. I have a youtube video of one of my autocross runs in my sig if you want to check it out, it was a good run until the end.

I have Adjustable Koni's on my 88 Mustang. I could not imagine anything else, I didn't know how to set them, but I experimented and that was fun in itself. Now the cars turns MUCH better. Really helped entry the most.

I will put adjustables on my 06 too when I replace the factory shocks. I'd bet on the Steeda springs too. I think they have more track time. Just guessing on that...

I think for an S197, the tires play a lot bigger role in dictating what you need for dampers and springs aswell. I have gt500 dampers with roush springs and they are great on 275 40 18 eagle gs-d3 street tires and is definitely an upgrade over stock (what isn't though). I pulled a G in them no problem on a road course. As soon as you put stickier tires on the car will grip more and then dip more though, warranting upgraded dampers/springs. If I could do it over again I would get Koni yellows and Steeda Sports or even competition. That is if I couldn't afford to get some coilovers. Then you get the option to corner weight which is worth some time.