Which part broke, the spout on the radiator, or are you talking about the metal pipe on top of the motor?
I'm assuming you mean the plastic radiator part,
OEM is fine but there are other radiators out there (mishimoto, etc).
Since you're in MN, I wouldn't worry about high temps too much
I've always liked using Gates parts for belts and hoses, water pumps and thermostats
Just make sure you install the thermostat with the jiggle pin facing upwards