Ok, I'm building an enclosure and I want to do this the right way. I will be using flexwatt and my question is, do I get a rheostat or thermostat to control it? I've never worked with Flexwatt before so it's a lil confusing...Also I'm making a double enclosure....Will I need 2 thermostats/rheostats? Is flexwatt sold at any hardware stores or do I have to buy online?? And one more question....I'm using PVC to build my enclosure...The flexwatt won't melt it will it, or should I Put something between the PVC and flexwatt?