From what everyone is saying, B&W's are very accurate speakers... hindi forgiving. If you put in a bad receiver, bad sound, if you put in a great receiver, great sound.
Suggestion ko is get a Marantz SR4200 or SR5200. Meron nagbenta dito ng brand new SR4200 for P14,000. If you have extra money, you can also get a NAD receiver.
Pero, kung for home theater use... kahit na gamitan mo ng magandang Yamaha, ok na iyon.
Hindi mahirap i-drive ang B&W unless you get the high end Nautilus stuff. Mas mahirap pa yung mga 4ohms na Dynaudio i-drive. Kaso, if you want to hear the full potential of the speakers, get quality equipment.