If you compare the diplomatic importance of the US and France and expected that their heads of state would have proportionate aircraft, French company Dessault has models that would suit Sarkozy.
The Falcon 2000LX takes 6 passengers, comfortably adequate for Sarkozy, his wife, a mistress, a private secretary and two bodyguards.
It can fly with one stop from Paris to as far as Alaska, in case Sarkozy wishes to consult Sarah Palin. It has a maximum takeoff weight of 42,200 lbs.
The Airbus A330-200 that Sarkozy has actually chosen carries 250 passengers in three-class configuration, has a takeoff weight of 514,000 pounds. That would, I suppose, be sufficient to carry all Berlusconi's personal retinue as well as Sarkozy's in the unlikely event that the two men chose to join forces on something. (I have seen no reports on what aircraft Berlusconi otherwise has at his disposal.)
The Boeing 747-200 that Obama has, has a maximum takeoff weight of 785,000 pounds and in standard three class configuration carries 366 passengers. (In fact he has two, on the principle that if terrorists manage to shoot down Air Force One, they have only a fifty per cent chance of downing the president. That seems a little edgy to me. Why does he not have a choice of ten? Or fifty? American paranoia seems to have lost the plot here.)
If Sarko had been truly unable to have controlled his bling-bling instincts, he would have ordered an Airbus A380. It has maximum takeoff weight of 1,235,000 pounds and in three-class configuration carries 555 passengers. He could have taken most of the French parliament with him. Or not.