I'm not a fan of waterfalls. I worry about how clean they can be kept. A dripper IMHO would be a better choice. That's not to say that misting or fogging shouldn't be done too. Chameleons need to be well hydrated....but not put in a situation where mold and bacteria can build up.
I don't know if spider plants are toxic or not and since veileds will eat vegetation its something that you need to be careful of. The plants should be well washed (both sides of the leaves) and if you leave the soil exposed, a veiled might very well eat it. Depending on the type of soil, it could cause an impaction. Pothos is safe for veileds to eat..mine have done if for years now with no ill effects.
As for the carpet...with high humidity, it might be a breeding ground for germs....and IMHO carpet is also hard to keep clean.
Using any soil or bark or chip substrate is not safe IMHO either.
You said..."for lights and heat pads what should i use"...what do you need heat pads for? Chameleons can easily go down to room temperature (high 60's) at night and its always been said to be good for them...and they are arboreal so they are unlikely to go and sit on a heating pad anyway. For lighting, they need a UV source (that is not through glass or plastic) that they can get within a foot or so of, and an incandescent light can be used as a basking source. They should not be able to get close enough to this light to burn themselves. The basking spot should be in the high 80's F. to high 90's for a veiled. The cage should have a gradient in temperatures...basking area hot and other areas of the cage cooler...so that the chameleon can move around to regulate its body temperature. If you live in an area where the chameleon can be outside, direct sunlight (not through plastic or glass) is always beneficial.
These are just my opinions. Others may have different ideas.
You have your work cut out for you!