If you are not a good handgun shot UNDER PRESSURE may I suggest a 12 gauge shotgun? Say a Mossie 18 inch barrel pump with a 4 shot tac-star side saddle and using Brenneke Black Magic slugs. That gun won't cost you even $300.
I mean a 600 grain slug at 1500 ain't hay.
Otherwise take the most powerful handgun you can shoot with accuracy and controllability. Preferably from .357 magnum on up.
This could be a 10mm, or .41 magnum, or .44 magnum, or bigger.
But whatever handgun you take do note: compared to that 600 grain 12 gauge slug at 1500 you see they are pretty puny.
“We can evade reality, but we cannot evade the consequences of evading reality” Ayn Rand