Consider sticking with a pvc enclosure rather than a tank. Tanks suck with humidity and heat and are much harder to regulate. You can get a T8 from Animal Plastics for $150. Shipped and with heat (flexwatt) included it only comes to $230. A T8 is 4x2x1 and could very well last her for her entire life. These cages make very nice display enclosures too - the black sets off the snake's colors really well and you can use whatever substrate you want and put in a nice driftwood climbing branch.