1) I assume you are talking about nephurus levis? go to
www.reptilesdownunder.com.au there is a guy by the name of Glen Roman, he can provide you with some info...
2) The price I have seen them for is 150 dollars each....
3) Try the above
4) The size of your enclosure is good
5) Heat mat will do just watch the temp
6) Why these species? geckos are great looking but generally not so good for handling.
7) You could use red desert sand with a moist area on one end of the tank. Otherwise a sandy loam for better digging....
