Where do I go from here?

I think you got good advice from @ghdprentice 

I would do a lot of reading and a lot of listening if you can before you dive in too deep. That might save you from making two or three upgrades instead of one if you can get it right the first time. I’m not sure I would go for an all in one device unless you are absolutely sure that’s going to be your endgame for quite some time. Separates give you more flexible upgrade paths. You seem to be pretty open minded about what path this takes, which is a good thing. Try to listen to various components that present different sound signatures so you can determine what really suits your taste. I wouldn’t just buy a brand or a model based on a recommendation. Try to give yourself options. 
As you move forward with this, I would keep room treatments pretty high on your list as your plan comes together. That’s something I resisted for a long time and that was a mistake. Getting my room properly treated produced more improvement than most components I bought.

good luck and keep us posted

These days automatic turntables are as good and sometimes better than belt drive but a lot of people are stuck in their ways and don't believe it. Buy what you can afford and what you'll use. If it's too much of a pain to set up and play records, you'll probably be less likely to do so. 

The audio quality I have right now is the best I have ever had in my life, and I am loving it!  Full stop.  Work on the room. Don’t change the system. 

You are off to a good start! I used to have Heresies from the 80’s, great speaker for that period of my listening, but definitely due for an upgrade. Start with speakers, take your time and find a brand/sound you like. I would not get hooked on B&W, nothing against the brand, but there are a lot of good choices. While not the best place to audition speakers and gear, I highly recommend attending a show to hear a lot of different systems. I attended AXPONA last year for this purpose and it was very helpful. 

The audio quality I have right now is the best I have ever had in my life, and I am loving it!  Full stop.  Work on the room. Don’t change the system. 

This is absolutely right. Even if you do decide to upgrade equipment, the room is 50% of the sound. Get that right, first, and then do the other upgrades. 

Just for starters: you, like me, have very low ceilings. That has to be addressed. 

Imagine you're eating a meal and there's ketchup all over some of it. Someone says, "You should try a better cut of steak." You would normally reply, "Ok, but will that have ketchup all over it, too? Because I'm not buying more expensive steak unless I know I can taste and appreciate it." It's the same thing, possibly, with your current room. Learn how to analyze it and be willing to experiment until it sounds good. Then go spend on gear.