If I were you I would first decide on which style of supercharger would fit your wants/ needs. ie roots or centrifugal. Once you have chosen that I would do some research on the different manufacturers of the style you like. There are lot of brands out there and each have their own pros and cons. Just take your time, do your research, then look for the best deal on the model that best suits your needs. Once you figure that out, im sure you can be pointed in a more specific direction for the exact model you want.