I haven't used one of Thermotron's chambers yet but I know of others that have. The website doesn't show the specs for the thermal shock chambers but it's worth checking out. I use a piece of junk Blue M and a 20+ yr old Ransco. What you're looking for is definitely top-shelf. Expect to pay big $$$.
http://www.thermotron.com/ther.html
Good luck, -Kevin
