Perhaps I'm a little confused;I thought the question was about ONE GUN for home defense.
As such carry outside the home will ONLY be in an approved,locked case,on the way to an approved,certified shooting range or other location outside NY City.The only reference to carry would likely be in the home itself and 24/7 carry comfort during the performance of common household duties would be the most useful requirement.
It seems most practical to choose a handgun that is small or light enough to carry 24/7,in a common major caliber,and with a conversion capability to 22lr for inexpensive practice...Before the gun is selected the buyer better have a COMPLETE understanding of the local law and regulations.
The buyer is after all in a city that I believe required It's sworn officers to carry DAO revolvers firing 158gr.lead round nose ammunition well into the 70's,well after other jurisdictions were clear on the hazards of that type of projectile in the urban environment.The law may only allow certain types or even brands of hollow points.(who knows for sure?)
Don't forget that unless we live in NY.NY,Chicago,Mass.Hawaii,the peoples republic of Kalifornica or a few other totalitarian countries within our federalist umbrella,it is almost impossible to understand this persons situation,but they must fully informed before they do ANYTHING.
I would however caution T.NY.Rev. to exercise most extreme caution in the rain,the reason being that I believe recent NY.law requires all official printing of the Constitution,the Bill of Rights and most particularly any publications concerning firearms or the Second Amendment to by code be printed on Bio-Degradable toilet tissue.
Good luck in your quest and remember:Ride Hard,Shoot Straight and NEVER SURRENDER.