Other Hotel Programs - Planning a trip to Italy; which hotel rewards program?

I'm planning a trip to Italy in May '13 with 2 friends. I've got about 25K Marriott points, 10K Priority Club points, 100K American points , and orphan points in various other programs. We're (hopefully) using United points for our flights.

Just wondering, in general, which hotel reward program(s) I should focus on earning points in that we could use in Venice, Rome, and maybe Florence or Sorrento. (Final itinerary is not even close to being set.)

I'll be watching for credit card bonuses. ;)

BTW...I did come across this post about Priority Club (IHG) properties in Italy:

http://www.flyertalk.com/forum/intercontinental-hotels-priority-club-inter-continental-ambassador/1313557-ihg-hotels-italy-all-you-need-know.html

I was in FLR last week and found St Regis to be a very comfortable property. I have the same opinion about their hotel in Rome. I wouldn't recommend Marriott hotels in Italy, as ( in most cases) they are old, dirty and basically worn out. You could try Grand Hotel Excelsior Vittoria in Sorrento and Luna Hotel Baglioni in Venice. They are both members of LHW. You could join their Leaders Club for $150 and get complimentary continental breakfast, upgrade ( upon availibility), free internet and a comlimentary night at any of their properties after every 5 stays at an LHW hotels. Only remember to book through their website.

My wife and I went to Italy in March '11 with our three kids. Stayed almost exclusively at Starwood properties, thanks to SPG Amex bonuses. Had to get two rooms everywhere as the maximum occupancy was 3 people pretty much across the board.