If your primary criteria is speakers that are physically invisible, you could drill holes on the ceiling or walls and mount individual drivers on them. That's going the DIY route.
Otherwise, you might be happy with satellite speakers from Mordaunt SHort, Boston Accoustics, Definitive and Klipsch Promedia. The satellites are about the same size as a Bose Accoustimas but better sounding and at lower prices. You may want to google search on these or check out Spectra for the Klipsch Pormedia and 5th ave for the Mordaunt, both at Makati Park Square.