Tazzy,
That is a very nice looking cobra that you have there. I had a NASCAR 427 Tunnel Port in one of my earlier cars but traded it for a 390 HIiPo as it just wasn't drive able on the street. If I remember correctly it cost me a grand total of around $4,800 back then. I also went in and talked to the Ford Dealer about getting a 427 Cammer, and the price was about what your sheet shows, but after the fiasco with the tunnel port I decided to stay with something that I could drive below 7,000 RPM.
Congratulations on your Cobra and I hope that you can find everything that you want soon.
Ron