Need (strongly recommend rather) batt grip also if the 70-200 is f2.8 one...if not very unbalanced on 550D. But I doubt the TS should abuse his/her fren and ask them to buy 70-200 f2.8 IS Mk II
The 70-200 is the f/4 version that she had listed. Not the f/2.8 one.
Don't know about Canons, but I don't imagine that it will be unbalanced with the f/4 version?