Welcome to the Boards, Fishmitch.
The stock header is really the end-all. There are other "race" systems out there, yoshimura probably being the most note worthy, that are a single header-and-silencer combo that are sweet for power, but a little lacking on the looks, IMO. Marving makes a nice one.
The big bore piston kit can be had on ebay any day of the week. If you can find the Yoshimura kit, good on ya, but it will cost.
The cam is best done at Megacycle or Web. Send them yours and they will grind and weld the profile you ask for.
The touring gear I'm not so sure about. Maybe Tucker-Rocky or Bikemaster?
Good luck with your baby four!
