I'm planning to buy the samsung galaxy s vibrant and what are the main differences between the other galaxy s models and the vibrant?

I live in Sri Lanka and the galaxy s is not officially distributed in my country. And almost all models of galaxy s can be found in the market and can be used with any network here.

I have looked at both of the galaxy s I9000 and the vibrant and noticed that the vibrant lacks the front facing camera. I would go for the I9000 if its just the vibrant with a front camera.

what are the difference between the I9000 and the vibrant? and which model should i purchase?

Thanks in advance!

 

and what about the other things such as hardware parts? display camera and the OS ? are they all the same ? is there anything that i would miss if i buy the I9000 instead of the vibrant?