Giant folding bikes are available in most bike shops, including R.O.X., Lifecycle, Paulina's, and Tryon.
Peerless bikes are available through its supplier here in the Philippines. If you're interested, visit the supplier's blog for more details on how to purchase this kind of bike.
The dealer of Flamingo bikes sometimes stock Strida bikes. Contact him for more details. Cutting Edge at SM Malls sell Stridas, but they place a high mark-up, so I suggest going straight to the dealer.
There are other folding bikes out there like Bike Friday, and Montague but they are not readily available in the Philippines. Many Japanese Surplus Stores also sell refurbished folding bikes for as low as P2,000.00. Reputable brands include Jaguar and Bridgestone.
Still want a Brompton? Help me convince Brompton to authorize a dealership here in the Philippines. Write them at Brompton UK.