2006 Chevrolet Optra Replacing the timing belt.

Timing belt change is due, the vehicle is at 58000+ kms.
I wish to know what else is required, gaskets etc when changing the timing belt.
I wish to use genuine parts, and since I have to travel 5hrs to the either Chevrolet Pampanga or Dagupan, I would like to be sure that all the parts and accessories are available when I arrive at these outlets.
Is this a task that most workshops can undertake, or is this a job that should be left to Chevrolet dealership.

I also have an engine management light coming on sometimes, it stays on for 10kms or so, then goes out. I've noted other posters, stating a warning ID, I don't have any ID symbols. Since there are no noted noises, temperature is normal, and the vehicle is operating as normal. I just ignore it as I understand that these cars are loaded with sencors.
Regards A4Skyhawk