Concerning the turbo on the R/T, it just depends on how much money and time you want to put into it. Choosing between the two, I would go with the SRT-4, a stronger start than the R/T and with the Stage 1, 2, and 3 kits for th SRT, it's a much cheaper and less strenious than putting a turbo on the R/T. I did not have an option for the SRT, I'm still a poor college student with through-the-roof insurrance prices.