looking for a stand mount speaker to match a s/s int amp.

Here a few that I like but never audition , so I am depending on your honest advise.

1. Nola boxer 2

2. Von Schweikert VR-1

3. Vienna Haydn Grand

4.open ...??

I pick No. 4, Open. 

But seriously, why don't you attempt to audition the speakers on your list?  As well as some others too?  If you cannot, then go hear some other brands that have similar design, specs and drivers to start to get an idea of what sounds best to you.  Not us!   Also, rest assured that your Classe amp will drive anyone of them with no worries.

Speakers are the most subjective component of all.  They all sound different and we all hear different.   You must hear some on your own.  That is my honest advice

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.

But one pair of speaker ,time to time listen with a tube or s/s amp.

If this the case, then strike off everything on your list and also what has been suggested so far. 

Time to start to auditioning speakers of higher impedance and sensitivity and find a pair to match the tube amp first.  Whatever you choose, your Classe will have no problems.  Good luck to you.