Looking for speakers for my 4W SET amp

There are a lot of choices.  A search on Audiogon will reveal a slew of threads.  My short-ish go-to list of SET friendly speakers include:
- Klipsch Heritage.  Heresy to Khorn, depending on your room and your budget
- Omega.  All good.  Speak to Louis for specific recommendations
- Coherent.  Great speakers from the great white north.  I own a pair of 8s and they are very good but I hear the 12s and 15s are fantastic.
- Diatone.  This is Japan's JBL.  A wide range of speakers in various sizes and configurations.  I don't think these guys ever made a bad speaker.  In the U.S. most models are branded as Mitsubishi (but not all Mitsubishi speakers are Diatone).
- Altec 17 and 19.  Big and bigger.  Other Altec models as well
- McIntosh ML-1C.  Don't laugh, these can sound quite good (in a vintage way) IF they are recapped and paired with the MQ101 equalizer.

4W is tough - depending on your space, how loud you like to listen, your choice of music, and even (perhaps) the length of speaker cables. It is right on the cusp.

thanks to everyone who contributed to this thread.  You've given me lots to think about

4W is tough

4W is more than enough, assuming that you select symbiotic gear and aren't trying to play in a concert hall-sized space.

My 45 Triode monoblocks put out 1.5Wpc and play plenty loud in my living room.  How many enthusiastic owners of decware UFO amps think 1.7Wpc is all they need?

You do need to pay attention to all the things gsm18439 listed.  As many have reported, I don't find that SET amps to be best for some musical genres like (obviously) heavy metal and techno.  Music with "too many notes" like large orchestral pieces are harder to get right on most/smaller single driver speakers.  But I have never heard a system that was perfect in every way.  Have you?

I have not heard the The TU-8200.  I have heard the TU-8600 (300B amp) and it is a terrific amp for the money.  I am a fan of the 6L6 tube, so I would bet that the TU-8200 is a winner.  I hope you find something that it will drive to a satisfying level.

From my experience, the kind of music that is hardest to achieve a satisfying or realistic listening level with low-powered amps is choral music, particularly acapella choral music.  At surprisingly soft subjective levels, the music seems to fall apart.

You are probably on the right track looking at Zu speakers--they are fairly efficient and easy to drive.  Zu's are very punchy sounding speakers; for some reason, the Zu representatives show them only with solid state amps, so I have not heard them used with low-powered tube gear.   Audio Note AN-K are nice speakers that are also not crazy expensive (they are warmer and more relaxed sounding than Zu speakers); I've heard them with fairly low-powered SET amps (7.5 watts/channel) and with push-pull 6L6 amps and they sound good. 

I have much preferred Lowther drivers used as wide range drivers (used as a midrange), rather than as a full range driver, but, they can be terrific as fullrange drivers in back-loaded horn systems.