I use the coconut stuff. It's fine, but not dusty. Easy to clean out and spot anything that needs attention.
I was really lucky and got my whole setup from a guy on craigslist. He told me to use cardboard and cover it with aluminum foil. I taped it to the sides and back of the tank and made one to sit on top. Holds heat and humidity well. You could even go as far as to make a removable one for the front. It's unusually dry right now in my part of WA and the house heat drys any moisture left in the air. I've been battling humidity levels the past few weeks.
You can get 60w day/night packs off petmountain for much cheaper than any of the chain stores. I change mine out every 6 to 8 weeks but you could probably get away with longer. They seem hit or miss on the life. Some will go 3 weeks others get changed out before they die.
I run the lamps and heat pad with this guy:
http://www.amazon.com/Zoo-Med-ReptiT...lla+thermostat
I am pretty sure I paid less than that for the one I bought. If you can get 2 life will be stress free!
If he's young he might not have figured everything out yet. Took my guy a few months to realize the temperature differences. He usually hangs out in there when he's full or shedding now.
Post up some pics!