I stopped by the pet store today in prep for my new addition and picked up some Leopard Gecko Dust (by TRex). Is that stuff good? I also got a jar of Calcium powder w/ Vitamin D3 (I know the D3 is not necessary, but it couldn't hurt, right?).

I was looking at their baby geckos and noticed they have an adult male for sale. Is it better to get one as a baby?
I have a 15 gallon tank with a ramp going to a 2nd level, for added floor space. Would that be too large and stress a younger gecko out? The adult looked very sweet and if he's friendly I might just bring him home with me Just looking for suggestions.

Thanks