I should start with speakers. This I know. I’d like to establish a new system.

Your on right path with the Volti's, horns don't require loads of power which helps to keep total costs down. Horns specialize in bringing performers into the room perspective, pair them with some 300B SET amp and you'll have the beginnings of a great system.

Starting with speakers is how I've always built systems, matching amp is absolutely necessary at this point. I also like the open baffle suggestions if you're after the performers in room perspective. They may require more from an amp so that's a consideration.

Over many decades I evolved from box to open baffle to horns, horns matched with SET amp is magic for me. Again, the Volti's would be a great initial choice, they're an evolution from Klipsch Heritage, that's saying a lot.

$20K budget means you will need to buy used to get max value. Even then you are going to have to be a sharp negotiator. 

I'd start with listening to different speakers where you can- dealer, friend, etc. Listen to the leaders in their class- ie: Maggies, Wilson, Sonus, Bryston.  Each type has a "voice" that is somewhat consistent throughout the type (ie: Electrostatic vs. cone vs. hybrid)

Once you pick out "your sound" buy the best speakers you can afford. IMO speakers have the most dramatic and identifiable effect on your rig. 

The next is a toss up- The saying  "put your money in your DAC" saying has a lot of truth to it.  Then your amp. IMO tubes are best for depth and soundstage but there are some fantastic SS amps out there these days that get pretty close. 

Expect about a year to get this all right- and maybe some mistakes along the way. The process is fun if you you're a journey kind of guy. Most here on these forums are. 

Lots of info offered some pretty good, others not worth the time.  We are a manufacturer of audio components and have been doing equipment repairs for 25 plus years.  We have heard more equipment than probably everyone posting here combined.  That being said:

Forget Harbeth 40.2 - consider the Revival ATALANTE 5 speakers at around $5K.  Better sounding in every way.

I am also hearing very good things regarding the PMC speakers from a  very good source although I have not heard them yet.  I was not a fan of the old designs.

The other speakers I would go listen to would be the Vandersteen Quattro.  You can get amazing sound from them even against setting them up against the wall.  That can be helpful if your wife is involved in this decision, etc.

Happy Listening.

Huh, what? He needs to buy used with 20k for max value?? What??

Speaker: Tekton Epic 15 ($2400, new, made in the USA)

Subwoofer: Tekton Cinema Sub ($1050 new)

Amp: Schiit Freya+ tube preamp ($1000 new) + Schiit Wotan poweramp ($2000 new, made in the USA)

Dac: Schiit Gungnir 2 ($1600 new)

Conditioner: Audioquest Powerquest 707 ($1300 new)

Sum Total, (new, made in the USA): $9350

Balance: $10650

I might just eat my hat if some 300k Daryl Wilson & D’oggastino rig sounded better. He even had 10k left over to get himself a nice suit, go watch some wind ensembles and dance companies.

$20K budget means you will need to buy used to get max value.

For $20K you can buy brand new and have a really good all around speakers. Consider a Coda CSiB Integrated Amplifier and Legacy Audio Focus Speakers. Contact James Thompson at Destination Hifi and I'm sure he would make you a nice package deal delivered to your door. https://destinationhifi.com/products/coda-csib-integrated-amplifier