Coming down Genting, learn to use engine braking instead of over relying on the brakes to slow the car.
you did notice the signs saying use low gear I presume... The 2, D3, at the gear lever are there for a reason.

Unless of course you are doing touge racing... that's the only reason i found where you might need to upgrade the brakes of the car.

Because DRUM brakes are cheaper... so the lower end models have drums... as you move up the range, generally all uses disc brakes,
plus disc brakes looks better.... and better looking car sells better...