Suggestions for whole system: amplifier + DAC + Volumio

Hello, starting my hi-fi system from scratch.
I sold my AV amplifier to buy an integrated stereo amplifier (I have to choose it based on the following choices).
The speakers are B&W 607 from 84Db. In the future I could also add a subwoofer. The room is about 18 square meters.

The system that I would like to implement - to avoid an AV receiver with HDMI again - is the following:

  • Smart TV connected via optical or coaxial cable directly to the amplifier (if the amplifier has an internal DAC: currently in my wish list I have NAD D3020, Denon PMA600/800, Onkyo 9130, Rotel RA11, Yamaha AS501. The budget as you see is 300-380 euros.

In order to improve the audio quality one of the following choices, with the plus of an external DAC (max 150 euro) or together with the amplifier one:

DAC BETWEEN RPI AND AMPLIFIER:

  1. Raspberry + Volumio with optical / coaxial output (or USB) attached to Khadas tone board and from DAC connection to the amplifier (analog RCA if the amplifier is provided with an internal DAC, or optical / coax if the amplifier has no internal DAC ). Alternatively Topping D30 or Schiit Modi 3.

  2. VIM + Khadas tone board. The ideal would be to exploit HDMI with OSMC system and for the rest Volumio but it is pure theory.

  3. DAC I2S: Raspberry + Volumio + Allo Player (BOSS or maybe better the Piano 2.1 to connect the subwoofer in the future) + Kali and connect to amp with analog cables.

USING THE AMP DAC:
4. Raspberry + Volumio + Allo DigiOne or hifiberry digi + toslink/coax cable.

The choice of the amplifier depends on which option is better to understand whether to buy an amp with internal DAC and whether it should have optical and coaxial outputs. If all this system is not worth in terms of quality, I may opt instead for a good 5.1 AVR to connect the TV via HDMI and use one of the above systems to connect Raspberry + Volumio via analog RCA bypassing the AVR’s internal DAC.

Thanks and sorry for the long post!