My suggestion would be for you to contact Sentry Safe's marketing company in Manila and ask if they have a distributor here. I believe it will be quite costly for one that size. I bought a smaller one 8 years ago and it wasn't cheap. An alternative we used at my former company was a chain with a lock that fits into most laptops. I have one you could try out and see if it works for you.
Zenorex is Sentry Safe's Philippines marketing arm, website with contacts is: Zenorex Marketing Corporation