What kind of baitcasting reel should i get for offshore fishing?

IM only 16 and i do alot of deepsea fishing with my dad but i only have one reel for it.(shimano spheros 12000FA) Now i want a baitcasting reel like my dads that can take on big snapper and im starting to get into catfishing and going for alligator gar so i kinda want it to be able to take those on also. thanks for the help.