I'm goin nuts

[eclypse_boy]

For size of an enclosure what should I go by? I've been told square feet of the base .75 per every foot of snake which would say a 4 x 2 is good for a 10 foot snake I don't like that. Then I've been told 2/3 the lenght but say my burmese grows to be 18' thats like a 12' enclosure I usually see them in 8' enclosures. Some one help me please I need 2 enclosures guyana red tail boa female and a burmese female I'd like to know what size is good for full grown.