I have to strongly suggest Boaphiles.

I use Boaphile cages and racks... love them.

Pros:
They come built and have heat already installed.
They look fantastic
The cages hold humidity very well.
viewing is top notch.
The are designed/built by a serious snake keeper/breeder that uses them for his snakes... you know they are quality.

Cons:
the black plastic does get stained by urates... some complain of them holding odor, but i've yet to see that problem, though I do take periodic cleaning seriously.