Speakers for triode tube amps

The budget is 10k, and they cannot be floorstanders.

@samuelg Well that limits things. At this point my recommendation would be a monitor sized speaker like the ZU Omen Bookshelf, and get yourself a set of Swarm subs to handle the bass. This will keep in in budget and yet you'll have full bandwidth. The Swarms are easy to integrate into the rest of the system and can prevent standing waves from messing with the room so you get proper bass at the listening chair. The Omens are easy to drive with most triode amps (we have a lot of customers with ZU products) and the size will work. The only bugaboo is ZU is sold out of them, but that could easily change soon. 

Another recommendation to look into Audio Note. I have an old pair of AN-E/Ls (92 dB efficiency). I am driving them with a 2A3 SET amp, 3.5 watts, and they will play way louder than I can tolerate, without distortion, in my modest 11.5” x 11” room.

The only way to know for sure is to try them, but it’s hard to imagine your amp won't be very happy driving ANs. They are just wonderful, musically engaging speakers, IME.

My TEKTON Pendragons are 5 ft. tall and running on an 8 watt SET from China....hahaha....Live sound concert style .Awsome and don't forget to get a Denafrips Ares 2 DAC...what a combo. And very affordable.

Dump the no floorstanders parameter & look at the Living Voice dynamic speakers..
IF you really must have stand mounts how about the Exotic Monitor from Salk Sound?

Merlin Music TSM are a smaller stand- mounted speaker that work very well with modestly powered tube amps. Read the reviews. There are a few threads here on Audiogon discussing amp options.
I’ve driven mine with higher powered amps like the Thor Audio TPA-60 EL34 based monoblocks and also a lower powered (16w /channel) KT88.
I play loud in a medium sized room (90 plus db at the listening position not uncommon, and 16x17x9 room)
These are excellent speakers if you like an honest presentation with minimal boxy colorations.