There is an awful lot of things to consider when creating a landscape design. Living in the tropics you have a great many plants to choose from. If you can afford it, hire a landscapr designer on a consulting basis. Having the knowledge of what works and the requirements of the many different plants you have to chose from and the time it takes to maintain them would be a real asset. I would talk to the most experienced person I could find and see if you can work something out. If his business is like most, he is eager to get what ever work he (or she) can in this economic climate. That is if the Phillpines is in the same shape as the US right now.