Honestly I'm not sure about Susu Farm Fresh availability specifically in KK or Kundasang area, I've mainly seen it at the usual chains like 99 Speedmart here in KL! One of my mum friends who travels to Sabah often reckons she sees it at the bigger supermarkets in KK town, tapi I can't promise lah since stocks vary, so maybe safer to call ahead to a few 99 Speedmart branches or Cold Storage outlets in KK just to confirm? Kalau takut habis, you could always grab a couple before your trip and pack in your luggage, especially since milk is not so heavy for just a small amount mah.