I agree with John and Ralph also - those three lenses make for a great combo.


If you want to save weight look at the 70-200mm f/4L IS. It's much smaller than the 70-200mm f/2.8L and (in my opinion) produces sharper results and the IS is magnificent for slower exposures.


The 24-70mm f/2.8L would cover reasonably low light and you already have the 50mm f/1.4 so you're covered anyway.


The 10-22mm is a fantastic lens as well - mine gets a lot of use. If that's pushing the budget maybe investigate the Sigma equivalent. I have a friend who uses it and is very happy.


If you could only get one of the lenses mentioned I'd go with the 70-200 f/4L IS.


Hope this helps.


Cheers, Ben.