First foray into tube amps

My relatively limited, but clear experience with tube amps shows that some modern tube amps sound almost exactly like solid state, and some people say that this is because of "modern sound" approach. Without sounding critical I would delete particularly Primaluna from your list, because to my ears this is exactly the case. I'm absolutely satisfied with my Unison Research tube amplifier in this respect.

As others suggest, work to audition each in your system (even if you need to pay for s/h and restocking).

My experience is limited to current McIntosh mono amps, which I heard at a dealer during a speaker demo.  The entire system was McIntosh, driving 50k SF speakers.  

I was disappointed in the sound, to say the least.  After two minutes I expressed concerns about the electronics (not the speakers).  The salesperson confessed that he knew the McIntosh line-up was no match for great speakers (his words), but McI were the only electronics that he had a the time.  

On the other side, McI has a fan base and retains re-sale value.  

Good luck,

Since you are in the US, Rogue is a brand worth a look.

I second the Aric Audio suggestion, he custom makes amp for people and will be able to make a recommendation for you. I’ve had an amp he makes on order since March, it is build to my requests to suit my situation. Transcend Push Pull.

I stopped reading when I saw the speakers, which are only 87db sensitivity.

I always recommend starting with higher sensitivity speakers if you are going to try tubes, or will have the option of tubes in the future.

I like 30 to 45 watts/channel tubes, (only 2 power tubes/channel) and I want efficient speakers so they have enough power for instantaneous peaks, and not driven hard so not so hot or a shorter tube life. 

Not always, but generally: If an amp only has two power tubes per channel and has a higher than 45 wpc rating, then they are running those tubes hard/hot.

Lower power needs gets you in best buying position: more options, less cost, less heat, less weight, and more options for placement, keep remote signal line of sight in mind.

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Some amps are good for 8 ohms, but not so good for 4 or 2 ohm dips in speaker’s impedances; others are very good for low impedance dips, pay attention to that.

Newer models have easy and safe bias adjusters and bias meters. That is desirable. Mine are internal, very inconvenient, and the amp has to be on, thus dangerous if you don’t know what you are doing, or make a mistake.