where are you flying from / to?
i agree with the beach thing
but it still may be hot..and it is peak holiday season so all the goodies in italy are going to be crowded... much better to go somewhere like florence off season

head for the hills...
go to barcelona and the pyranees
or northern spain - santiago de compestela
or lake como in italy and then switzerland

if you want green and cooler = NORWAY!!

i did a two centre holiday to italy/portugal
i used easy jet to go to portugal
http://www.easyjet.com/en/book/index.asp
http://www.ryanair.com/site/EN/

please ask if you have any more qs - i have guide books for all three of your mentioned destinations