Hi,
I am not sure that the 3200 will handle well with 19 inch alloys,but i would guess that you will need to ensure that the production of the alloys conforms to the speed rating and torques of the 3200.
I would hate for you to be blasting down the road and the wheels deform due to stress levels never meant to be encountered in the alloys fitted and never tested on a maserati and lets face it not that many cars do over 130mph let alone the 180mph that a 3200 could reach.
I would like to go 19 inch on my 4200 but if i did it would be a set of genuine wheels for me personally.
all the best