I was having issues with warping and decided to build a heater to try and prevent it. I ordered everything through www.omega.com.
This was used with http://www.thingiverse.com/thing:4772
Bill of Materials:
Temperature Meter with Alarm or On/Off control Output with Audible Buzzer
Model No. DP7001 - $83.00
- Ready Made insulated Thermocouple
Model No. 5TC-GG-J-24-36 - $33.00
3.Polymide Film Insulated Flexible Heater
Model No. KH-808/10-P - $74.00
I also purchased a power supply cable from a local hardware store.