Hi @notji143 ...
First, I don't think the iphone 4 is still available for purchase as from what I know, only the iphone 5 is being sold now and soon (November 15), the newer iphone 5s and 5c. Please refer to this link for your choices http://shop.globe.com.ph/phone-gallery.html?manufacturer=93
If you are not interested in a Globe line which would lock you in for a period of time, a prepaid kit is available for purchase but I'm afraid that Globe would not want the phone to be amortized as they are not in the business of doing so. Instead, they may suggest to you to arrange for an installment scheme from your credit card company in case you purchase such from Globe.