sadly some things have changed since 1990 when Rita took her trip. It has become outrageously expensive to ship bikes in airplanes. And good luck spending less than $100 a day for the two of you unless you're willing to travel in the south.
Time of year is VERY important in Italian travel. you say "the summer" but if you can avoid August in Italy, you will be doing yourself a great favor. Everyone in Italy goes on vacation in August and the popular vacation spots are inundated with tourists from all over Europe. Road travel is nightmarish because everyone in Italy is trying to leave home and go on their own vacation.
Good luck. i'll be there in late september myself.