I use a set of HT-10s for the track for the front rotors and stock pads for the rear. I noticed that the rear wheel had chunks of debris stuck to the wheel, most likely due to the heat... I'm not sure how this effects braking but I would get matching HT-10s for my rear...
But to answer your question, it really depends on what type of track you're at and how you drive the car. I'm sure OEM pads would be fine but they will heat up fast.
Current: 2005 Interlagos Blau Metallic M3 ZCP
Gone but not forgotten: 2006 Smoky Granite Mica IS250 AWD
Gone but not forgotten: 2005 Red Honda CBR 600RR