All do quite well in captivity if you take the time to understand their requirements. . The most common would be the Colombian BCI. As far as enclsoure size, depends on sex and ssps and you. IMO, boas thrive well as adults in 4-6ft enclosures. But when it comes down to it, it depends on how much room you can afford to give the animal as well as how many you plan on keeping.

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Basic supplies....boa, cage, water dish and heat...maybe a hide or two for the young ones.