Radiant heat panels are nice, but for terrestrial species, I definately prefer flexwatt. It is NOT going to melt the plastic unless you're plugging it straight into the wall without some kind of thermostat or rheostat/dimmer to control the temps. The plastic in a vision cage doesn't melt at anything close to 90 degrees.
I believe you meant 6 x 3, not 6 x 2. A 6x2 really isn't going to be of any more benefit than a 4x2 would just because of the shape, just too narrow. heating a 6x3 vision is easy. You're going to cover the screens meant for lights with saran wrap or cut out pieces of acrylic or whatever, to keep the heat and humidity inside the cage. Using foil tape you'd just tape about 3 foot of 11" flexwatt to the bottom of the vision cage at one end, and plug it into a good thermostat (I don't trust cheap ones at all, you do not want a thermostat failure, and don't like on/off types, prefer proportional, alot more stable), or rheostat/dimmer and monitor it with the use of a temp gun. Like I said, Radiant heat panels are nice, but just in my personal opinion I feel they are more suited for arboreal species since terrestrials digestive process benefits from the belly heat. Cool side temps are also easier to control when you're not directly heating the air. 90-92 degree surface temp on the hot spot and the rest of the cage to stay no lower than the high 70's is text book perfect if you ask me.
