I must be different than the others, there is no doubt in my mind that I would get a turbocharger over the supercharger. You will get the best horsepower per dollars out of it, plus if later on you decide you want more power you can upgrade (i.e. diff intercooler, turbine, upgrade your fuel system, pistones, rods, etc.), with a supercharger the amount of power you will be able to get out of it will platough(misspelled) rather quickly. This is just looking at horsepower per dollars, there are other factors as well. They are both a kit, whichever one you choose I don't think the installation difficulty could vary enough where you would pick one over the other just on that. Just my oppinion, I would go with the turbo kit.
-Matt