No, to break it down, you have three generations of iPhone; 8GB, 16GB, and 32GB.
A 3GS iPhone has roughly double the internet speed of a 3G. It was an update put in place by Apple when they faced complaints that the internet speed was too slow. I do not believe 8GB 3GS iPhones are available, only the 16GB and 32GB, since I have never seen them come into stock. I may need correcting....



