Suggestions for my system

Looking at a budget of around 5k.  I always search for used stuff on Audiogon so it’s feasible I could nab a component that lists for 10k at my budget. 

It looks like you have a pretty nice setup already.  Have you tried moving the system into a larger space and sitting farther away from the speakers?  You may find that you have more of those qualities you're seeking.  It may be challenging to get that "expansive" experience you're seeking in a small room. 

I have a system set up in a similar sized space - ARC VSI 55 integrated and Focal 1008 BE speakers and an SVS SB12 NSD sub.  It sounds fantastic, very detailed, dynamic, and fun to listen to, but it does not have the same scale and soundstage of my main system which has much larger speakers and more space.  I've tried larger speakers in there like my Klipsch Heresy, but they are too much for that room.  The Heresys sound great in my slightly larger office which also has a much higher ceiling.

Room treatment might also help.  That's something I haven't tried  yet.

You might try adding a small subwoofer.  That should help.

You might be expecting too much from that small space.  Perhaps others that have found a way to achieve the nirvana you're seeking in a small room can chime in.  I don't think replacing your current gear is necessarily the answer.

You should try the Harbeth P3ESR. I have owned both the C7 and the P3. In that size room I think you will find the the smaller P3 will give you outstanding results!
Here ya go!
https://www.bing.com/videos/search?q=harbeth+p3esr+review&view=detail&mid=5D7EB69CCEBBAAE793...

My main goals in hifi are an expansive soundstage in width and depth, and holography.

You want Synergistic Research. Speaker cables, interconnects, power cords. If you like what you have and want to get that expansive width and depth and holography without changing the overall character of what you have in any other way then what you want is Synergistic Research HFT, PHT and ECT.

These will all improve imaging allowing your speakers to disappear while throwing a wider, deeper sound stage. Search around a little, you will find everyone who has actually tried these is beyond satisfied. Its mystifying how they can do so much which triggers the usual suspects. But among those with actual experience there is no doubt. They all come with total no-questions return guarantees. Because they are that good.

They all produce roughly the same effect in roughly the same proportion but since you have a turntable I would probably start with PHT. The PHT come in different "flavors". I think Black Widow is overall the most neutral, while Green Dream leans a bit to the more liquid smooth side. Purple Haze is the only one I did not care for. They recommend one on the cartridge but try more, I have one Green Dream and one Black Widow on my Koetsu, plus one more Green Dream on my arm, and two ECT on the arm base. And one more ECT on my motor pod.

ECT you can use all over the place on just about any component. It seems like they might work better placed inside and directly on things like caps but I tried that and they work just as good if not better on the outside. We watch movies and sticking one on my laptop improved both the video and the audio so much my wife noticed without me even saying anything. We're talking serious, significant improvement here.

HFT will open up your sound stage like you cannot believe. Follow their recommendations, they are pretty good, and by the time you get to the Speaker Kit, well it is simply amazing how well they make your speakers disappear. Try em. You only thought you were hearing imaging! Ha!

Best of all these are "keepers". They come off as easily as they go on, and all will work wherever you go and whatever you upgrade to down the road. Keepers. 

I agree to add room treatments; absorbion and diffusion.
 In my 12 x 16 ft. room, a few panels helped shape the soundstage and focus the 3D image.