Tube amps vary MUCH more than do solid state amps as far as sound is concerned. You will have to hear a variety to land on something that matches your taste and your particular system. Some tube brands try for a sound that is closer to solid state sound than others. An example of this is Audio Research. For my personal taste, that is too lean (not warm) a sound, but, I respect that brand because they remain consistent and true to their particular sound. Other brands, such as Audio Note, stay fairly consistent in their choice of a warmer sound.
There is a general difference in the sound of high powered tube amps that use multiple output tubes in parallel and lower powered tube amps. I much prefer low-powered tube amps because higher powered amps tend to have a "hard" and "brittle" sound--there is an artificial hard edge to the attack of some instruments and vocals. I priorities a sound that is more natural, and relaxed sounding (but certainly not muddy or slow) and lower powered amps more often deliver this kind of sound. I have 99 db/w efficient speakers so I get away with a 5 watt per channel amp. For a speaker like your Stirling, I would think 20-40 watts would do. Do I give away bass extension and punch? Perhaps, but no amp is perfect and I prioritize other things.
What all good tube amps deliver better than solid state amps is a sense of liveliness and dynamics at lower volume levels; you don't have to crank the volume to get the music to come alive. If you need to play at lower levels to avoid annoying other people, tubes are the way to go.
To get the benefit of tubes, it is better for the power amp to be tube-based than for any preamp/linestage to be tube based. The classic hybrid approach (solid state output) really doesn't deliver the best that tubes can offer.
Of your listed choices, I like the CJ. It is a touch on the "polite" side and does not deliver the dynamics and vivid sound of the best amps, but, it is still quite good. As I mentioned above, I find Audio Research amps to be a bit to lean and hard sounding, but, that is purely personal taste. I've never like PrimaLuna amps--they sound both hard and dead to me. I've only heard Quicksilver a few times, and they sounded okay. I really did not like the sound of the modern McIntosh MC 275; to me they sounded lifeless; I also did not like the very shoddy construction and the way they cut corners to keep cost down.
I've only heard one Aric Audio amp and it sounded pretty good and the construction looks very solid. It would be worth your time to consult with them on what might work with your speakers.
Most of the brands I particularly like are a bit out of your price range. Synthesis Audio makes fantastic sounding gear, some of which are in your price range, but what I really like for the money is quite a bit more--their A40 (40 watts per channel) integrated amp. Likewise, Audio Note is out of your range, but perhaps, you might find something used.
Vintage amps would be the way to go for finding something terrific well within your budget, but, getting into that game probably requires some experience and some help with re-conditioning older gear. Amps made by the likes of Scott, Eico and Fisher can be extremely good (avoid vintage McIntosh because the sound is okay but the price has been driven WAY up by collectors). If you can find experienced help or a good dealer of vintage gear, you could find stuff that beats any modern under $5,000 gear.
Good luck on your search. If it works out, I think you will like what tubes offer.