Ball python housing and heating help?

OK i currently keep my ball python normal in a glass tank and have it heated by a heat pad. I am looking into getting more, and maybe in the future breeding them, so i want to keep them in sterilite containers because i already have a lot of reptiles and dont want any more glass tanks. In the future i will make a rack and use flex-watt heat tape and use a herpstat thermostat but for now i will just keep them on shelves in sterilite containers. I have two questions. What size container should i keep a baby ball python in and will plain old heat pads melt through the plastic container (if they are just plugged directly to the wall?) Thanks.
-Edward

I have a zoomed UTH, but I'm afraid to use it without something to control it like a thermometer, so you should get one with the UTH. Follow it's instructions, I think they usually go on the bottom of the tank.

will a rheostat wind up messing me up?

Get a thermostat. You need one if you want to use a heat pad with a tub. A rheostat can still spike temps over 100* which is enough to burn your snake.

no a rheostat is a real cheap (15$ thermostat) will that mess me up?

I am not sure what you are trying to say..
Just to clarify, a rheostat is like a dimmer switch. A thermostat uses a probe to regulate the temperature of a heat source.
A rheostat is about $10.
The cheapest thermostat I am aware of is about $25. The reptitemp 500r.

I am not sure what you mean by "mess you up" but yes, a rheostat will make it harder to maintain constant temps.

thanks