The hard parts you need to cool an LS-powered NA or NB. Radiator, fans, upgraded wiring and hoses. These are the parts we use on our own cars, tested with years of hard use and proven to be effective. They're also custom-built for this application so they fit right in - no bodged up generic parts!
Note that the radiator can take our FM fan kit in either an NA or NB. If you want to use factory NA fans, they will also bolt on. Factory NB fans or Brand X fans that are designed to go on normal NB radiators will require the extra brackets.
Also, the upper radiator hose included with the Completion Kit is intended for LS3 style water pumps that have the top water port facing forward and just left (from the driver's perspective) of the throttle body. If you're using a water pump from a different engine that has the upper port facing forward but just right of the throttle body, you'll want to plan on picking up a different hose - Napa hose part number 9030 (or equivalent) should work for these applications.