To use a 180 tire , you will need to get a 5.5" rim for the rear. This has been done by mrplease. I like the look of the larger rear. I am not sure how much it changes the flickability of the 696 though.
Ducati offers a set of Performance rims for the 696 that are 5.5" wide, and will accomodate a 180 reaer tire. Moving from a 160 to a 180 will slow down your turn in a bit and may require a little more effort to get the bike into the corner. I track my 696 with the 160 and don't feel the need for a 180. However the look of a 180 is very appealing.