amazingly I was able to find 4ft "rubbermaid" like containers. They were holiday containers for christmas trees.
But just find about the biggest one there is. Not meaning taller, but longer and wider, and it does not have to be rubbermaid. There are other brands of plastic containers out there. Check around, and if you find one you like, but the lid doesn't seem to fit. Just use bungy cords to keep it on nice and tight.
As long as the uth is controlled with a lamp dimmer or something that does the same effect, then it should be great.
Make sure to measure the temps with an indoor/outdoor probe digital thermometer. Put the theremometer directly over the uth on the inside of the rubbermaid.
You shouldn't have to use bulbs or anything. I just use a lamp sit a little back and turn it on for daytime/nighttime cycles.
Drill holes all the way around. Put substrate, hides, climbing sticks, water bowl. Whatever you normally put in there, put it in there.
I think that the plastic containers are alot more heat resistant than everyone thinks. I've had my temps (because it got hot outside) spike up to 102 degree's (with a cool side of 80. so it's not like they were cooking) and the plastic was still fine.
-----
1.1 Ball Python, 0.1 motley amel corn