LOL to a mini-van?? are you kidding?!?!? You would need to beef up the internals of the engine otherwise anything over a couple of PSI and you would blow it to hell and back. I am sure you would need to upgrade the suspension components as well....man o man why would you supercharge and fart cannon up a mini-van?!?!
Supercharging your minivan would cost more time and money than it would be worth to most people. Just drive it like it is and save for something better.
Edit: Also, those electric superchargers are worthless.