Boardman Race headset question

Hurricane Warrior
Hurricane Warrior Posts: 147
edited May 2014 in Workshop
I'm trying to find which bearings I would use for this bikes headset??

Been having a grinding noise coming from the headset when steering, totally stripped it down and cleaned it up, the bearing are quite rusty so thought better to replace them??
Jamis Xenith Endura Sport 2012
Boardman Race 2013
Genesis Equilibrium 2014 (Built myself)
Boardman Comp MTB 2016