Believe it or not you can get a supercharger for under a grand. You'll just likely have to do it yourself if you don't plan on spending much.
Call around to certain junk yards/scrap yards. Many of them will be very happy to give it to you for cheap so it doesn't just sit around collecting dust, or having to sell it for scrap metal value.
Bare in mind, the chance at finding one at a scrap yard is pretty rare. Most junkyards take the blowers out with the motors and try to sell it all as a whole, others are more willing to separate the blower from the engine. It is a pretty rare thing to find sitting in the junk yard, but it's certainly worth a try.
You can also try craigslist or eBay.
As far as chips. Look into the company Unichip. I don't have experience with them, but I hear good things.