I can't say what "is" recommended to imply that I speak for the entire chondro community but I think most would agree that the cage should be made of a material that is a good insulator (wood or a "good" plastic), solid top for mounting a heat panel (preferred heating method by most) and side ventilation so the heat and humidity isn't sucked right out the top.
For young chondros, many people use basic rubbermaid or sterilite tubs. Nothing fancy because the animal will eventually grow out of it. If it is a neonate or yearling, I would spend more on the thermostat than the cage. Here is a link to one example of a tub setup: http://www.finegtps.com/cagingbabies.htm
You can also use a rack style setup using tubs. I prefer this over the example above because it is more energy effecient. For cages, here are some links for examples. I can only recommend the first two from personal experience. Note that with the Barrs cages, many have screen tops but he will make them with solid tops at your request.
http://www.pvccages.com/
http://www.herpcages.com/
http://www.boaphileplastics.com/arborealcages.html
http://www.repti-racks.com/
If you have good carpentry skills, you can build your own. Here is a link illustrating a good design: http://www.finegtps.com/cageplans.htm
Good luck,
Bart