Anoying semantic point: both are BCI (boa constrictor imperator), they as just further identified by locale each of which has its own set of unique features but not enough to consider them different subspecies. Some locals do, however, have their own subspecies like Suriname and Guyana which are both BCC (boa constrictor constrictor) or Argentina's BCO (boa constrictor occidentalis). And just to make it even more fun, it is now preffered to drop the "constrictor", so it's just st BI or BC (but hopefully not BO). Incidentally, almost all morph animals you see; albino, motley, hypo , etc will be BI.
I highly reccomend reading The Complete Boa Constrictor by Vincent Russo, its like a boa bible. Great info on care and husbandry and encyclopedic listing of all locales and subspecies.