Wow a 100 gallon tank??? That size snake will do fine in a 15-28 qt or a 10 gallon. Spray paints when heated can release chemicals that can kill your snake. All you need is 2 plastic hides, paper towels/aspen for bedding, water bowl and a UTH on thermostat. If in a tub drill holes in the sides, if in a tank cover the top but maybe a 4"x4" hole with alumium foil. Your snake will out grow this in maybe in about 3 months depending on snake. Then you can upgrade to a 28 qt or 20 gallon.
Snakes don't grow into tanks they grow out of them. The more safe and tight fitting their area feels the happier and the better eats they will be.