put this question on Vitz Fan club and hope you will get the answers.
Usually the difference is not very big. Some seats are slightly different, some has back viper, some has little wide bonnet, some has 8 airbags, some has only 2, etc. thats why they give different name to each model.
But engine is same 1KR-FE.
Here we have to choose among the models which are available here. Because no one cares to see these details before importing vitz.