DIY Soda fridge incubator?

I've been playing around with the idea of possibly breeding, if I ever decide too I will most likely build my own incubator.

I saw the DIY sticky thread on this subject above. I was wondering what is a good price for coolers similar to the picture below picture below? Working one and not working? How many clutches would this hold?
Can a working be use as an incubator?- Adding the heating elements and not plugging it in?

http://i331.photobucket.com/albums/l...psuvvuv0tv.jpg
http://i331.photobucket.com/albums/l...pshnnlyvie.jpg
http://i331.photobucket.com/albums/l...psrrkkhrmf.jpg

Thanks for looking :D