timing belt ba ika mo? get OEM bro. costs a few hundred pesos more than replacements. to cite an example, a mitsubishi lancer's replacement t-belt costs around 900, OEM costs 1600. for a hundred pesos more, you get peace of mind.
My suggestion is that for critical components, go OEM whenever available. Kung wala, go original. Of course, I assume by OEM you mean the same manufacturer as the original, example (kahit not critical components 'to): KYB for Honda Civic shock absorbers, NGK for Mitsubishi spark plugs, etc.