Btw, are there any Classe Cap 151 owner's here at Audiogon ? and what speaker mostly they match?
At 150wpc into 8ohms and 225wpc into 4, just about any speaker ever made.
Tube integrated amp ..next purchase after speaker.
If this your intention, why are asking about speakers that will work with the Classe solid state integrated? You do realize that once you go to tubes, the speakers that a much lower wattage tube amp can drive will be become far more limited. In fact, I would strike all three speakers on your original list off because they would all be poor choices with a tube amp.
You need to determine what kind amp you really want first and then talk about speakers. Solid State and Tubes are two whole different things.