Any "common boa" these days can be a mixture of different things.
Because of morphs, localities, and people/breeders willing to cross things, unless you have specific data from a very trusted breeder, it is very hard to know .
I have seen photos of "common boas" that look like that. I have also seen morphs that look like that.
I have a Barranquilla, Colombian BCI. It's a "common boa" sort of.
Gus Rentfro produced this animal and he is as serious a locality breeder as it gets.
Oddly enough you can see some Key West morphs that look quite similar but they are morphs.
Pick up a copy of THE COMPLETE BOA CONSTRICTOR if you want to learn a bit more about localities and other types.
Also,,, if you do in fact have a male, it will probably not get that big. You might want to consider holding onto it as it is a beauty.
Set up a nice display cage and just enjoy it.