Help building first tube system.

Hi Walstib, I think Tomic has it right. Start with the speakers. You really have to go listen. Would you buy a car without looking and driving first?
The speakers will 95% determine the sound of the system. Stand mounts are fine but you may want to consider subwoofers with them as none of them go very low. Everything else? I think build quality and durability are of first importance and I would stick with well established companies with good reputations like Audio Research, Macintosh, Atma Sphere and Manley. You should probably spend 10 K on speakers and 10 K on everything else.

Mike

At your budget I would steer you away from some of the "pedestrian" brands of tubed electronics like: Prima Luna, Schiit, Rogue and a few others that I cant recall. These are not bad products, just not nearly as good as others that cost a bit more. Within your budget you can easily afford separates which will always outperform an integrated. I would put as much money into the components and speakers as you can and then upgrade cables and other tweaks (be careful!) as your budget allows. Fundamental from day one are good acoustic treatments for your room. To suggest almost one third of your initial budget on cables and tweaks is absurd and bad advice IMO. I have limited experience with Atma-sphere preamps but the amps are among the best I have heard given the right speaker impedance. 

your 20K budget is more than sufficient to build something nice. Many of us choose amplification or speakers first and go from there. Good advice I've seen in this thread is "buy the best speakers you can afford." I have  a 20K system and half was spent on the loudspeakers.

Thanks to all who have replied.

The room has 10’ ceilings. Walls are drywall but ceiling is wood. Basement room, concrete slab with pad and carpet. 
Intrigued by the Raven line up of integrated tube amps. Anyone else have input on these? What about Cary?  
I guess I should ask the question, any recommendations on a reputable tube amp dealer in Chicago? Couple hour drive but probably the best starting point.

Thanks again and keep the advice coming!

To your question about Cary, I owned two Cary amplifiers, an AES/Cary AE-25 and a Cary Sli-80 F1. I was very happy with both but replaced the Sli-80 with my Raven Audio Blackhawk LE. Cary was started by Dennis Had and he was responsible for how highly regarded Cary gear has been. He still builds and sells amps under the Inspire brand but is no longer affiliated with Cary. Here's a discussion from a couple of years ago about the company and its products that may be helpful.
https://forum.audiogon.com/discussions/since-dennis-had-left-cary-has-the-company-built-any-new-tube-equipment