1) 3H x 2 x 2
2) If you want to let the crickets run free but have them not escape, you'll need to use small wire mesh. It really diminishes the room that the chameleons have to walk, though, as they can't grasp the sides. You can also get those plastic reptarium (??) dealies... they are black,cricket proof, and decently priced.
Dish feeding, if you're feeding crickets (as opposed to mealworms or silkworms which can be kept in a relatively shallow dish) you can use those big icecream tubs. The crickets can't get out of there. Put a piece of egg carton and some food for them, and the chameleon will eat when its hungry. I prefer dish feeding because they never escape, they don't crawl on the chameleon and bug it, the chameleon doesn't have trouble catching the food, and it's just easier to add food and see how much the cham is eating.
3) You can use hardwood or just go with particle board that has been sealed with a water based sealent. Avoid woods like cedar and pine, as the fumes are toxic (mostly with cedar)
4) Define low cost? If you have 100-150$ to spend, you may just want to go with a reptarium, they sell them at petsmart and you can get a good sized one for that price. You could build one for 70-150$, depending on materials, but don't forget the time involved.
5) The reptariums are classy looking, but either way, as long as you dress up the inside with plants, maybe a water fountain, etc, it will look great! Just try and avoid making terribly crooked cages
6) Well, you either buy or make a dripper, and "aim" it over a particular leaf and watch where the water drips. Just place a dish there to catch the water. Or you can buy an 8$ water pump spray thing from home depot, and just spray for 5-10 minutes a day, and they'll drink that.
Good luck!