$3000 stand mounted speakers?

generally, ANY stand mounted speaker will have less bass than ones with large cone drivers which is fine unless they try to do too much, ports, passive radiators, ...

My advice is to avoid rear or side ports, if ports, front only, to avoid rear/side reflections that diffuse directionality.

Consider where a STEREO PAIR of self-powered subs would go now or in the future. IF/when you add those subs, hook them up in a way that the tube amp no longer needs to amplify the frequencies the sub will handle. both your amp and mains will be happier, thus you will be happier.

+1 for Watkins Gen 4. 
https://www.theabsolutesound.com/articles/watkins-stereo-generation-four-loudspeaker/

Lots of options recommended here for monitor speakers.
Of the suggestion here for $3k, these are the ones that initially intrigue me as a step up from the ProAc Table 10 I've been considering at $2k.
They would look nice in our place too, w/o taking over (WAF).

Omega Super Alnico Monitor
Dynaudio Special 40
Totem Signature One
Reference 3A de Capos (wood veneer version)

As a purchase w/o hearing, I think I'd have an easier time reselling if it doesn't meet my expectations too.

If you'd be open to purchasing a pre-owned speaker, I'd recommend you look at the Totem Fire monitors.

The Harbeth P3 ESR will sound great with your EL34 tube amp. I have owned both the standard model and the anniversary edition. A perfect fit for that size room!!
https://www.bing.com/videos/search?q=harbeth+p3esr+review&view=detail&mid=5D7EB69CCEBBAAE793...