First, before you built anything, you need to keep in mind that each cage needs to be designed for each specific species needs. Sure there are species that have identical requirements, but considering you havent chosen a species as of yet, I think you are getting ahead of yourself.
Another point that should be made is that cages should be sized appropriately for young chameleons. A 3 month old chameleon (most common age to buy the majority of species at) would not do well in an enclosure so vast. You'll need to keep a temporary enclosre of say 12x18x24 for a chameleon youngling.
Depending on which species, the cage walls will be different materials, you may need more of less contained humidity, more of less importance for an automatic mister. As far as Ceramic heat eemiters, I already explained the importance of using a true "light/heat" bulb. The Ceramic heat emmiters seem to such just as much humidity from the air as bulbs do, and more.
I don't know of anyone using proportional thermostats with these types of chameleons. Reason being is that they are generally smart... and will move in or out of the heat, regulating themselves. There are few cases of chameleons burning themselves, however this is usually due to a fallen bulb, or a bulb that is set too close to a perch that site under the light-- the position of this perch may not be correctly aligned to allow them to stay within the heat, but back off a bit. You can correclty ensure this is possible by having angle snating branches beneath the heat lamps, allowing the chamleeon to shuffle up/forwards-down/back and choose they temperature they wish.
Another note is that some types of heat bulbs do not do work with diming thermostats at all, or do not do well with proportional thermostats as the filament cannot handle the on/off adjustments.
Actually, it completely slipped my mind that a Propagation mat would be waterproof! I goofed!
As far as donating, Brad, our wonderful creator, founder and generous site funder would be the one to contact. Him and I have personally discussed moving the site to an exclusive server and adding in some more complex real time chat features, possibly a bought program since they seem to be of higher quality.
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2nd reply:
I just dont see any need for a heatmat. Unless you have gravid females, pygmy leaf chameleons, or improper caging... chameleons will spend a vast majority of their time in the upper 2/3rds of the cage, as it should be.
There are a bazillion types of bulbs that can be utilized for heatlamps, you just have to find the one you like best.
I want to note that you show diligence in insuring that each detail of your future chameleons care is looked after, and diligence is absolutely one of if not the most important trait for a chameleon keeper, aside from an open mind and a thirst for learning.
glad to have you onboard.