My son is 11 and I've traveled with him since he was 3 months. It's a little easier with one because many hotels have rules on how many can occupy the room. Often we are upgraded to a suite and have a rollaway in the living for him. I"m not sure you'd be able to fit two rollaways in a suite or if that's even allowed. I suppose it would be best to call SPG and ask.
As far as France and Italy, I'll give you the run down on some of the places we've traveled with our son. I hope it helps and feel free to PM me if you have questions. Also, please remember families travel differently and this is just what has worked for us.
France: We typically rent an apartment in Paris and prefer to stay in the 3rd, 4th, 6th, or 7th. I have stayed with my son at the Westin Vendome. The room had two double beds-might be a tight squeeze for four. This isn't my favorite area, but I was in a pinch needing a place at the last minute. It worked but was very expensive.
Have also stayed at the Sheraton CDG. Just the two of us this time, had a king bed. It was great for our early morning flight.
Italy:
Rome-stayed at a non SPG boutique property.
Florence-Westin Excelsior. lovely. Had a big suite with a huge patio. rollaway for kid. Worked great. Great PLT recognition
Venice-Gritti Palace. suite with rollaway. excellent stay. Great PLT recognition
Milan;non SPG boutique property.
Lucca-B&B. would just do this as day trip
Milan-non SPG boutique
Bolzano-non SPG boutique
I would highly recommend Paris & Rome to begin with. You may end up needing to book two connecting rooms.
Again, message me if you have questions. I'd be happy to help.