Two Row, copper or brass. Three row if running an A/C or doing lots of commuter, stop and go traffic or idling a lot.
Be sure to match your coolant to what the manufacturer of the rad suggests. I personally run Prestone 50/50 pre-Mix in all my vehicles but aluminum block motors have different needs and requirements.
FYI, Flush the coolant system out! Thoroughly!!!. Don't forget the heater core and hoses if you are still running them. You can flush or back-flush, which latter is only running the flushing solution through the system backwards. Pop the thermostat housing off and check the T-stat. This is a good time to replace it while the system is being serviced. There is even a T-state variant available that, if it fails, it fails in the opne position so coolant will keep moving and not overheat and blow out into the overflow container. Same-same goes for the hoses and their clamps. The radiator is just one part of the cooling system and it being new just means that all that old stuff you kept now becomes the weakest link.
Nick