Actually to cater for smog, fog and better visibility, the bulbs will be required, otherwise, stock bulbs will be working perfectly fine.
Are you sure regarding this "H"? i.e. Vitz uses H4 type bulbs? Please confirm.
I think, I will stick to halogen category. LEDs are quite expensive, produce extreme light and accordingly; much heat. Xenon / HIDs are a big No!
Kindly confirm "H" type for Vitz (i.e. H4. H7, etc.)