IS and IS II lenses

Hi All,

I am planning to buy the Canon EOS 600d with the kit lens.

I checkd in Clifton cameras - they offer for 455 pounds IS kit.But I find in other places the camera comes with the IS II lens 18-55 mm.

Is there any difference between the two ? I see none in DP lens comparison.

Also Amazon offers the IS II for 450 pounds .But the doubt I have is, does it come with a warranty ?

Clifton offers with canon warranty.But after checkin its the IS lens I stopped ordering.

Please suggest me.

Thanks,

Sriram