What is the best cage for a BRB?

[Zodiac]

I have my Brazilian Rainbow Boa in a 20gallon Long tank. Now she is getting bigger and bigger and am now wanting to get her adult home. I'm looking for something that is 4ft long x 2ft deep x 2ft tall. I was gonna build my own out of Melamine but time has become short and won't be able to build it. So, now I'm looking into buying one. Some examples of companies that make them are...

Vision Cages
Monster Cages
Animal Plastic

I'm looking for something that can hold humidity very well (85%-95%) and is affordable. Any Ideas?

Also if you use any that have been made by companies, if I can get a review on what you think of them would be great!

[BoaMan Jon]

Animal Plastic, Boaphile, and Herpcages.com are really nice plastic/pvc cages that all hold humidity very well. I'm not familliar with Monster cages and I never really cared for Visions or Neodesha reptile cages.

If you can afford it, go for the AP or the Boaphile cages.

[Reptile Dude]

I have a couple Animal Plastics cages and they are awsome. This spring I am going to do my whole snake building in AP cages and racks.

[LdyDrgn]

We use plastic storage tubs for ours... they hold humidity VERY well, even with lots of airholes.