I just got my bci almost a month ago. He was about 16 inches when I got him, but I really think he has gained a few inches since then!
He is a really easy to handle snake; not at all head-shy. He is very bold and inquisitive when handled. I feed him only one large mouse per week; switching to small rats soon.
I have never owned a bcc, but I know that like Randy said, they do get much bigger than your average bci. I am not a large person, so I wanted to stick to something smaller (well, if you could call 8 feet smaller, hehe.)
About the snake you handled... BCIs have more of an ovalish shape to the lighter parts of their backs; BCCs have a more "puckered" shape to these markings. Boa-constrictors.com is really helpful. here's their site on BCIs... http://www.boa-constrictors.com/com/com.html
If you search their topic bar on the left, you cna find out about bccs and other boas. I hope I have helped!