Your question is which first… definitely speakers.
@hoosierinohio …”audition…”
+1
You want speakers that really appeal to your emotions.
In the long run speakers typically will be between 30 - 35% of system… but no set rule. Most of us do this over a long time. once you have speakers you want to break them in and know what they sound like before upgrading the rest of your system. So, get a few hundred hours under your belt before considering the rest.
All electronic components are equally important. If carefully chosen then Streamer = DAC = Preamp = amp in cost. Don’t think the streamer does not make a Hugh difference… it does.
So, your interconnects are great until all else is done… and you are recovering from the major purchases. Choosing wires are best done after everything is broken in and you completely understand what your system sounds like.
Be not in a hurry. I remember early in my audiophile days, wondering around listening to speakers for weeks, they all sounded fine. Then a tear rolled down my cheek on one set of speakers… I had them for about ten years. Great choice for me.