I have just booked 4 nights in Florence and 2 nights in Venice for the carnival
and I am wondering what kit to bring. 
I currently have a Canon 450D and I own a Sigma 18-50mm F2.8 (consideriing upgrading to the 17-50mm OS version) and a 55-250mm IS. My most used focal length is the 18-50mm, often at the wider end.
I am presuming for shot's of the masks I would need a fast telephoto lens - would a Canon 85 f1.8 be useful?
For Florence I am considering hiring a Canon 10-22mm (16-35mm eq) or buying used (and then selling) a Tokina 12-24mm.
So for this trip I would take with me my Sigma 18-50mm f2.8, a fast telephoto, and an ultrawide. Does this sound about right for this trip?

I currently have a Canon 450D and I own a Sigma 18-50mm F2.8 (consideriing upgrading to the 17-50mm OS version) and a 55-250mm IS. My most used focal length is the 18-50mm, often at the wider end.
I am presuming for shot's of the masks I would need a fast telephoto lens - would a Canon 85 f1.8 be useful?
For Florence I am considering hiring a Canon 10-22mm (16-35mm eq) or buying used (and then selling) a Tokina 12-24mm.
So for this trip I would take with me my Sigma 18-50mm f2.8, a fast telephoto, and an ultrawide. Does this sound about right for this trip?
Nabob!? Pretty close, I suppose