I too have heard the Gamut D200 is unbelievably transparent, but I have not heard one yet.
Of the amps I've heard/owned, the pass labs aleph series and the ayre v-1x are the most tubelike sounding of solid state amplifiers. The ayre would be a good choice for your high power needs. I am using mine with the notoriously power hungry eidolon speakers to excellent result. I would like to try out a monster (i.e 250watts+) tube amp with this setup some day.
The ayre sounds like 1/2 solid state and 1/2 tube. The he instrument textures and harmonics are correct, it has a sense of space and presence, but it's not as liquid as a tube amp. It's also more transparent and a gazillion times more powerful than any tube amp I've heard. It's the only solid state amp I've heard that I MIGHT 'blindfolded' guess is a tube amp. No transistor grain whatsoever.