Reddit reviews Zoo Med Reptile Heat Cable 100 Watts, 39-Feet

You'll need a thermostat, a cheap DIY way:

http://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/

Not too hard to put together. Or as others have mentioned a Ranco or Johnson if you don't feel up to the task. Note that the "eBay controller" is DUAL stage, so you can control both heating and cooling. Depending on your environment this may or may not be very important. For instance, my chamber is in the garage so I need to be able to control both heating and cooling during certain months. Some commercial products also do this...for a price.

For heating I use:
http://www.amazon.com/gp/product/B0002DIWTG/ref=oh_o00_s00_i00_details

But I just started using heat this fall. Has been working well so far, the cable does not get hot to the touch, only warm. Since I installed this in a chest freezer that acts as cooling (which worked excellent this summer).

I just made a fermentation chamber and used one of these. You can get shorter lengths if you don't create a huge chamber. It works fantastic so far. Not a single complaint.

http://www.amazon.com/Zoo-Med-Reptile-Cable-39-Feet/dp/B0002DIWTG

Here is a link to my build post. Towards the bottom of the album, you can see how I installed the cable.

http://www.reddit.com/r/Homebrewing/comments/2ja8tc/finished_my_fermentation_chamber_complete_with/

https://www.amazon.com/Zoo-Med-Reptile-Cable-39-Feet/dp/B0002DIWTG/ref=sr_1_5?ie=UTF8&qid=1495749709&sr=8-5&keywords=Repti+cable

It's amazing, and as far as placement I just have it randomly placed on the floor of the freezer and it's fine. I plan to tape it to the walls with electrical tape eventually.