Peruvian boas are known for being one of the larger of the BCC localities.. I have a picture of one that's well over 10' long. Peruvians are known for gaining yellow color on their bodies as they mature.. with red tails of course.

Venezuelan boas are not commonly seen for sale.. in fact I don't ever remember seeing one. Surinam, Guyanan, and Peruvian are the three most common BCC boas.

I can't tell you if you'd be ok with a boa constrictor as your first snake or not. If you can, handle and be around some large adult boas that belong to someone else to see if you feel comfortable with them. They are very strong, even though most are quite docile.