Well to start you may want to use the search button. There is a site that sells kits but they are a bit pricey. The site is www.trubendz.com. Your better off picking your choice of muffler(s) and bringing them to an exhaust shop to install them.
Check out some sig pages for ideas,including mine, I also have a 00 R/T and I'm running dual flowmaster 40's with magnaflow tips.