I was choosing between D.tinctorius or D. Leucomeles and also R.varibilis
Just to add onto that - big no no, especially for vivs that size and without having cared for each animal separately before. If you are even thinking of going down that path you will need experience and lots and lots of space and time. The requirements for geckos and darts are just too wide apart (temp, humidity, UV lighting, etc.). Otherwise you'll get animals fighting and eating / killing each other (even if its something as simple as chasing them away from food).Mixing species is a big no no.
Search for "mixing" and you'll find lots of threads explaining why.
On the moss/leaf litter, if you've just added the lead litter on top of the moss then the tank is still going to hold too much moisture, and it'll rot your leaf litter very quickly.