Plastic Breaker Panel Enclosure
I would encourage you to Google zinsco panel failures or federal pacific panel failures just look at the images and you will see why I don't believe they are available. Anyone that has replaced a panel from a failure will tell you the only thing that prevented the home from burning was the sheet metal enclosure. This is not just these 2 panels brands but even the big boys like square D, siemens and cuttler hammer. I had a big 3 phase burn holes in a buss on 2 legs and this was only a 30 amp breaker in a panel full of 100+ amp breakers. Bad things happen all the time even with top of the line equipment.  Would you trust your home to a plastic panel after looking at a few of these images? 
Yes some of the parts are plastic but as you will see in many of the failures the plastic is gone but the enclosure is intact.