determing a power kit for amp
 

alright i've never really understood how you come to decide what amp kit/fuses and cables you need for your amp.

im asking this because im getting a new amp and its hard searching for an amp kit.

crutch field tells me that people would get a 100amp - 4 gauge amp kit for the amp im getting which is the Kenwood KAC-9102D...so what determines what i use and what i need to get?