Most BCI females stay around 8' I believe, but I'm no expert. If you have a BCC, then it's a whole other kettle of fish.

Cserpents also makes cages, and I've heard good things about them too. When I purchase my cage, I'll be looking at constrictors nw, cserpents, and animal plastics.

I am intrigued by the boamaster pvc cages, but have heard he can be hard to get a hold of (I think he prefers to be called). Avoid boaphile, all I've read about him points to long delays and bad communication, but again, I have no personal experience.