What is the difference between these models of the Mazda rx-8 2006-09?

[thecool]

I am a first time buyer and I really like sports cars and just coupes so naturally i love how the mazda rx8 looks and been interesting in buying it for a year now, but i noticed it has three different models like the mazda rx8 sport, the mazda rx8 touring, the mazda rx8 grand touring. basically i was wondering what was the difference between the three models pros and cons and which was better to have. info would be great in my buy and much appreciated