Welcome to Geckos Unlimited! Firstly, the Giant Day Gecko is more of a solid green with red compared to the Standing Gecko. They are both diurnal and are part of the Phelsuma family. Personally, for a pet, I would choose the Standing Day Gecko, but they are similar, and it is your descision. Giant Day geckos won't like to be handled as much as other geckos, and they are realitively bigger than other Phelsuma geckos.