I would take some time to research some of the more readily availible species, and then decide which you'd like to work with. Then we'll help you track some down.
Its hard for us to tell you where to go look if we don't know what you're looking for. Most people that work with Phelsuma have some species, but not others.
You should look at P. laticuada, P. m. grandis, P. quadriocellata, P. standingi and maybe a handful of others, but the before mentioned species are readily available and are great to work with.
Let us know what couple of species you are trying to decide between and we can give you some pro's and cons of each.