First, I've seen some with stainless steel interiors. That'd be expensive as hell for a new one, but I checked Craigslist and there are plenty with blown compressors available cheap.
Second, sous vide is all about cooking low and slow. How low? What you want to serve at. So a side of beef would be about 135, and pork would be 160. Plastic should stand up to that pretty easily.
[edit] Here's a good one. https://www.flickr.com/photos/riverrats/sets/72157628074571836/
Now to see if he ever updated with the details.
Second, sous vide is all about cooking low and slow. How low? What you want to serve at. So a side of beef would be about 135, and pork would be 160. Plastic should stand up to that pretty easily.
[edit] Here's a good one. https://www.flickr.com/photos/riverrats/sets/72157628074571836/
Now to see if he ever updated with the details.