Hello,
I own a pair of Anacondas, an 8' Green Anaconda and a 10' Hybrid Green x Yellow Anaconda. I can honestly say that they are a lot of work and mantenence. They do require a lot of room, but no more than a Retic or Burm would really. My Anacondas are in 8' long x 30" Wide x 2' High cages and can live in them for quite some time. At least until about 16 feet. My 8' Male Green is very tame and I have had it since it was about 2 weeks old, it's very calm and doesn't mind being handled at all. My 10' Green x Yellow Anaconda isn't what you would call calm, and it's very hard to move around, it's not very snappy, but pretty squirmy. Anacondas are great snakes as long as you get the right one, and have a lot of spare time on your hands.
I have pics of the snakes and cages if you want them. If there are any questions, I will be happy to answer them! I know this post is a little late, but it will do.
~Ben