As others have recommended, start with speakers and audition as many as you can -- ideally a few at a time at each dealer so you can get a sense of what you like. Your room will play a big part in how they sound so buy from someone that will let you audition at home.
Re: Paradigms -- you don't necessarily have to get Personas. The new Founders series has the 120h which has built-in powered subs and bass room correction which can help tune to the room. They also won't be as bright as the Personas. That said, there are many other speakers that have a completely different sound signature that you may like better. Vandersteen Quattros are a great recommendation for any room but so are speakers from Dynamikks. Couldn't be more different, but both are incredible.
Amplification -- way too many choices here but you're looking for something that goes well with the speakers that you choose. Mcintosh is great and if you want something where guests come over, recognize it, and go "wow" -- then Mcintosh is the only brand that others will know and do that with. Also has great resale. For great sound at a better cost, though, there are lots of options that are better. Once you dial in on the speaker that you like, try tubes vs solid state (A vs A/B vs D) to see what you like best.
Digital Source -- I'm a fan of Roon with a streamer. Great user interface. That means getting a Roon server on your home network and a streamer near your amplifier. Alternatively, get an Aurender or Lumin or similar and just stream directly from the various streaming services. For DAC, I like Denafrips but there's also Holo Audio and many others to try in your target budget.
Vinyl Source -- have no idea as I left vinyl behind quite a while ago. (I still regret it a bit but no going back now)
Room treatment -- you have rugs, a big heavy couch, and cathedral ceilings -- you're already in great shape. Professional room treatment will definitely help optimize the room but you have to balance that with what you want the room to look like. I have a dedicated listening room in the basement with low ceilings -- so I need a lot of room treatment. You may not. I'd get the system in the room, get it where it looks and sounds the best and then consider room treatment. If you're really concerned about the room and how it plays with your equipment, the other path would be to get a preamp that has built-in DIRAC or similar or do room correction through Roon for your digital source.
Happy shopping.