Sorry, I somehow missed to reply to your questions earlier.
I do not have a Gecko morph at the moment. I have planned to release some new Animal Morphs in the upcoming weeks, maybe I can add a Gecko-like morph then.
1. Haven't worked with Unity for a longer time, so I don't really know how the characters work in Unity now. I think you'll have to choose a special shader, one that supports Normals & Displacement maps to re-create the fur effect.
2. You can always use my characters as a base to create your own customized ones with different textures and accessories. You can also use additional morphs to create your own shapes. I don't really know if you can morph Sammy into a Chihuahua, but you can definitely try it
. I think some manual work in an external modeler is necessary to get the best results.