moving coil speaker for tubes

You've got the right idea- take a look at
http://www.atma-sphere.com/papers/paradigm_paper2.html
for more information.

Good choices include (but are not limited to) Audiokinesis, Merlin, Coincident Technology, Ref3A, High Emotion Audio, Ridge Street Audio, Vandersteen, Wilson...

If in doubt look at what the designer is using. If he is into tubes, you will do well. If the designer uses transistors, I'd look elsewhere.

Try changing the speaker posts and let them break in. That will change the sound more than anything.

wlfbmf, dont be an a-hole.

Easy now. Anyone who knows their audio would never, ever use that combo with stock posts!!! Try different cables. I know a dude who makes some killer stuff. You want the hook up? Bet you never heard anything even close!!

Atmosphere listed some very good choices, and there are even more available if you are into DIY.

I have owned Rogue preamp and amps. I have always found them to be a clean, clear, non-tubey sounding equipment. Based on this I think I understand what you are looking for.

Changing speaker posts, by-passing is even better, will possibly allow more details to come through but won't do anything for speaker colorations.

I'm not sure I would agree that there are speaker made for SET. There are certainly very efficient speakers, but that just helps SET work with them. The coloration that you have heard with such speakers could very well be coming from the SET. Like speakers, some SET are less colored than others.

Also, there is nothing wrong with running very efficient speakers on 150 watts/ch. I have added a second 50 watt PP amp to my horns and the improvement in bass control, as well as enhanced separation, is amazing.