In this video it seems like the 535 vs full bolt on dct don't make much of difference from 20-120mph. By the way, there is not much road to play here on Oahu, other then airport and H3. You should also get wider tires something like 295 rear and 265 front for more traction if you are planning to supercharger it.
http://www.youtube.com/watch?feature...&v=rJXyeORKFfs