You may be thinking of something like this:
INTEX Krystal Clear 1,200 GPH Cartridge Filter Pump & Saltwater System
That model cannot be used with another pump and filter. What you probably want is one of these two models:
Intex Krystal Clear Saltwater System

Intex Krystal Clear Saltwater System 28661EG -- product info
Intex Krystal Clear Saltwater System 28661EG @ Amazon

Intex Krystal Clear Saltwater System 28663EG -- product info
Intex Krystal Clear Saltwater System 28663EG @ Amazon