Here is a great chart I found. I personally prefer "true red tails" (bcc) over the bci, but there are also some nice bcis. I just thought I would post this for newer members.
----------------------------------------------------------------------------------------------------------------------
Boa constrictor amarali, Amaral's boa
Boa constrictor constrictor, Red-tailed boa
Boa constrictor imperator, Common northern boa
Boa constrictor longicauda, Tumbes Peru boa
Boa constrictor melanogaster, Ecuadorian boa
Boa constrictor nebulosa, Dominican clouded boa
Boa constrictor occidentalis, Argentine boa (locally known as lampalagua, ampalagua or boa de las vizcacheras) [3]
Boa constrictor orophias, St. Lucia boa
Boa constrictor ortonii, Orton's boa
Boa constrictor sabogae, Pearl Island boa