Hi Pap
the model 17 is the full size and the model 19 is the next size down. You can use the longer magazines in the model 19 and there are 33 round magazines that fit in all of the 9mm Glocks if you are in need of some extra capacity. They stick out a bit for concealed carry however
Look at both the 17 and 19
The 9 mm Glocks all run great, there have been some issues with the other calibers

Peter