They are completely different.
I consider Kouros Cologne Sport a lighter version of Kouros. Personally, I love Kouros for being the strong and bold fragrance that it is - I see no need for a lighter version of it. But some people like Kouros Cologne Sport just for that reason.
Body Kouros is nothing like Kouros. It is more of an oriental/gourmand fragrance. I personally like this one a lot.