I was in your shoes, OP. Lots of great ideas. Here are some thoughts.
Interconnects, power cords, speaker wires. I spent about 1100 for all of it. I bought all mine from Pine Tree Audio, an internet seller. Sounds fine to me. There are several others that are reasonable. I would not go wild on wire.
Streamer: the top selling is probably blusound about 600. There are also ways to lower noise on digital sources. This becomes a separate post. In general, power cord upgrade, get rid of wall warts. Inline filters such as NA Eno or Ether Regen. Hard wire ethernet to streamer, cat 6 or higher.
DAC. I would keep the one you have now.
Preamp/amp: Nice integrateds available now. Integrateds take less wire and space. You can buy tube or solid state. Tubes are a warmer, lusher sound. Tubes dont work well with inefficient speakers. there are some high powered tube amps; most are less than 50 watts. Solid state more detail power better at running low impedence loads. Hybrid(tube preamp and SS amp) integrateds available. You could keep the one you have now. Rogue is a good value, they make a variety. A class A/B amp usually have more power but run Class A at lower volumes. Class A are usually lower power and warmer sound, Leaning towards tube sound. Class D are detailed and energy efficient. This is a general classification sound signature and power matching between amp and speakers are important.
Speakers: Most speakers are what I call inefficient. Either low sensitivity or low impedance drops at certain frequency ranges. Horn speakers are more efficient. They can be harsh if built cheaply or paired with wrong components. It sure would not hurt to try other upgrades if you like the general tone of your speakers.
Other: have you spent time with speaker placement? Component isolation can sometimes really open things up. Cover windows and or buy room treatments. Do you have enough power or the right speakers to fill the room?
Phono: I skipped this for several reasons. It can be incorporated into your preamp or be it’s own component. I didn’t add this to keep down costs and clutter.
These are general suggestions to get you started. I would spend on several things. It would help if you have a dealer handy or friendsto help.