Match of amp power and speaker power handling

I am still pretty new to the high end audio world so my question is probably pretty basic. I am very confused about how much power I should look for in an amp (I'm talking separates, not a receiver) to best/appropriately drive my speakers. I have B&W 604's Series 3 that are rated (conservatively according to B&W and the dealer I purchased them from) at "25-200 Watts into 8 ohm on unclipped programme". My initial impression was to purchase an amp that is rated at no more than 200 watts. I have since read from numerous sources that one should actually have a higher power rated amp than the "maximum" rated power rating of the speakers in order to provide enough "headroom" power to accomidate the very short duration spikes in power requirements that music demands. I have read once should have an amp that delivers at least 150% the "maximum" power rating of the speakers and that most speakers are damaged from running an underpowered amp into clipping rather than to much power. I understand this concept but how do I know what is too much power putting my speakers at risk. Thanks for any infor anyone can provide.
Totaly of base. Power is required to drive inefficient speakers. if you speakers are efficient 10 watts will work.

604 dont need 200 watts of power. Many look to watts to make up for thier other short cummings.
A lot depends on how loud you plan to play your speakers, but the "150% rule" does seem to me to be overkill.

A home theater system would need an amp/speaker combo capable of greater dynamics than a music only system, but I think you'd be really surprised how little your amp has to work to play loud. If the input/output impedances of your electronics are well matched and your speakers have a mild impedance curve and are fairly efficient, 10 watts could conceivably be sufficient.

My ProAc Responses 2.5s are manufacturer rated at 25-200 watts. I've used different amps including solid state amps rated to 250wpc, but am currently enjoying most a 37wpc Bel Canto SET40 tube amp.

I'm a definite believer in quality over quantity. That said, there are a lot of quality high powered amps out there.
I am a big fan of quality high power. One can never have too much power. That being said you may never use all the power you are buying, so you don't really need a 300 wpc amp to drive your speakers. A quality Solid State amp in the 100 wpc to 200 wpc will work great with your 604's. I don't have much experiance with tube amps but have found that you can also get great results with less tube power than what you would need with solid state amps.
Yes, a clipped amp has more chance of doing damage than an overdriven speaker by too much wattage. That's because the waveform of the clipping tends to burn out tweeters.

But odds are you won't play anything loud enough to cause that.

To answer your question simply - a 100 or 200 watt amp should be fine. And, so you know, to your speakers, a 200 watt amp isn't that much more powerful than a 100 watt amp.

Bob Wood