What would be better...
Getting a component set that handles that power but one that he hates tonally, or finding a set that may only handle 150W yet he loves the sound of? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif In the latter case, they'd be plenty of headroom, wouldn't have to worry about the amp ever nearing the clipping threshold...
Buy a set because you like how they sound, not their power ratings. That being said, the Boston Acoustics Z6's will eat up that power daily.