Congratulations for the new car.
Its fuel efficient car but if feeded with the correct oils & choice of exact tires.
Gear oil and power oil are same.
All companies gear/power oils are good.
Give priority to
Liqui Moly
Ptt lubricants
kixx
all above three companies are perfect to choose. Now decision is yours and as your pocket allows.
For engine oil, though you didnt ask, but frankly i hate the local companies oils like caltex, shell, total, pso, suzuki, toyota, honda, etc. All these oils are rubbish and not durable even original oils.
If previous owner was using havoline 20/50
I will suggest to choose oil 10/40
priorties are
liqui moly
ptt lubricants
kixx's tin pack oil is good also. But only tin pack.
If previous owner was using zic a+ or zic a,
then choose ZIC OW (0/30) and change interval is 6k. Subject engine is in really good condition.
If previous owner was using suzuki oil, or petron (20/50), or zippex, or sinopec, then i will suggest to choose
liqui moly's 20/50
ptt performa 20/50
sim3 (20/50)
all the best.