Same watts at 8 and 4 ohms?

invalid,

Here are some amps (more like welding machines) that can do double the power:

D'agostino Relentless.
Pass labs, almost all their amps.
Boulder 3050 monoblock,

and there are more......

@mt9894, one of my restrictions is that for these speakers to stay in the living room, the stuff driving them needs to be fairly small and discrete.

The H2O is only 14x14x 6-in tall. All black and one small LED in the front, it easily disappers.

If performance to you is most important then it can't be beat. Look at the inside in that 6moons review. You will not find that in any $2K amp and the ability to drive Scintillas.

If size and looks are more important then there's plenty of class-D amps that are simply modules thrown together in a shiny chassis.

You can't have it all.

Cakyol,                                                                                                 those amps are underrated on there 8ohm power specs there isn't any amp that can actually double it's output power, it is impossible. Like Georgehifi says it would be perpetual energy to be able to do that. I have a krell amp that claims that spec but it can't technically do it, it can come close but the lower in resistance the less likely.

I have a krell amp that claims that spec but it can’t technically do it

What a lot are doing is to underquote the 8ohm wattage to make the 4ohm look like it doubled.
  
You see it all the time now in the Stereophile spec bench tests, where the manufacturer says it’s 150w into 8ohms and 300w into 4ohms the gullible see this as doubling. Then Stereophile show the 8ohm is actually is 200w measured and the 4ohm remains still as 300w, nowhere near doubling then. It’s not illegal, but also not honest either.

I’ve been asking Stereophile to "call them out on it" now for ages in the measurements section, but at least they measure and show it for the reader to make up his own conclusions about it. Suppose they have to be careful where there advertising dollars are coming from, and not to rock the boat too much.

Cheers George

     Better amps have very robust power supplies that can provide the extra current required to double the power.  For example, an old 125/250/400 Audire Forte at 8/4/2 ohms respectively, has one 500 watt transformer and 4 26,000 mf filter caps per channel.  A very fine Bryston 200 wpc amp, of that era, has a 375 wpc transformer, and 2 4000 mf caps per channel.  Guess which one the bass drops out of at higher volumes, or with more demanding speakers.
     A pal bought a set of B&W DM 14's from me for his 125 wpc Marantz super receiver from the same era. He decided to get a second set, like he had heard years ago at my house, powered by this 125 wpc Audire amp.  The Marantz absolutely would not push all four to nearly the same volume, and it lost a great deal of bass, and pinpoint accuracy.  This reciever is stuffed with a tuner, a preamp, all kinds of switch gear, an FM dial, etc.  There was no room for a big power supply.  
     Ever wonder how a Marantz A/V receiver can push all those channels at 125 watts per?  I have one, It can't. It can move the sound around, but that is all.  A separate sub amp is absolutely required for this type of thing.