We use these connectors and pins on our hot end wiring harness:
Male connector pins, 24-30 AWG Digi-Key 16-02-0108
Female connector pins, 22-24 AWG Digi-Key 16-02-0102
Male Housing Connector 4POS .100 Digi-Key 0701070003
Female Housing Connector 4POS .100 W/LATCH Digi-Key 0050579404