Proturing or roadrace rear suspension

Not sure if this is the right forum for this but I'm going to toss it out for comment. What type of rear suspension works best for protouring or roadrace/autocross? Should I stick with the standard springs and use caltracks or should I consider a four link of some kind. I have also considered an independant rear suspension. There are a number of options on the market. I would have to do more work for an IRS but I can do the work. Any comments? Anyone with personal experience would be appreciated. :glasses7: