Well, you're not saving too much on this eBay auction in comparison to just buying them straight from Alessandro so I think it would be safer to just buy straight from the source. You can buy the case seperately if you want one.
The 'i' is simply a newer version of the Alessandro MS1. There are some improvements but they are not huge. I wouldn't worry about it too much.
The MS1 is based on the SR125 and is therefore definitely better than the SR80, as long as you can deal with their sound, which is more neutral than the typical Grado. You will not get as much of the trademark Grado brightness and clarity, although the sound character is not exactly completely different - just a little bit more tame and neutral.