I am lucky to own an Experience Music two box phono stage using 56 triodes and 7788 (E810F) tubes in the signal box with 394a mercury rectifiers in the power supply box. Jeffrey and Dave Slagle built mine to spec with dedicated mono phono and stereo inputs and two line level inputs. Likewise, I use a bespoke two box line stage with 71A triodes in the signal box and 394a mercury rectifiers in the power supply box. Fit and finish are extraordinary. The sound is sublime; open and holographic with great bandwidth and speed. A misconception of tubed gear is that it is slow and syrupy; my preamps are FAST but preserve plenty of tone color and a density of information I've only been able to hear with tubes. As I've upgraded the components around them, I've come to appreciate my pre-amplification even more and regard it as a true end of life product.
One advantage of using tubes is the ability to tailor the sound to your particular sonic palate by rolling tubes. Jeffrey typically uses tubes that are plentiful, long lasting and reasonably priced, although he does have the option of using Western Electric globes if you wish. The boxes get warm but do not noticeably heat up my small listening room. One note: my preamps are HEAVY, each box weighs between 70-90 lbs! They have a demo unit that you can listen to in your system but be aware, it is not built to the same spec as a final unit. You will however, get a good insight into what the preamp can do. Alternatively, perhaps we can arrange a trip to the Pacific NW for a demo. PM me if interested.
I've heard the OMA at their Manhattan store; in the context of that system it was wonderful. I also really liked the Thoress and Tron amps when I've heard them. I find Shindo gear interesting. I like the aesthetics and if you listen mainly to jazz and chamber music they could be your ticket. There is definitely a "Shindo sound". My impression is that if you go the Shindo route, you are committing yourself to an all Shindo system to really maximize things. I've heard the Wavelength gear at RMAF and I'm can't comment because I wasn't a fan of the speakers he paired with but Gordon Rankin has a good reputation in SET circles. Unfortunately, I have not heard the Line Magnetic gear but it does look intriguing.
Good luck