Next upgrade for my analog source

So what do you hope for this upgrade should do for your listening pleasure? 🤔
Will help to maybe narrow down those choices, methinks. 
Michélle 

Ok, "upgrade the listening experience"...
That may mean different things to different folks, so let me try what I have to say. 
This is of course always based on individual experience 😉
Where to get the most bang for your buck I'd say is important in far away places.
I live in South Africa, so I guess I can qualify for this. 

Your EAR 834P I've heard, my son has/had this one. Slightly euphonic but since you like it and I thought it was jolly nice too, that would stay in my opinion.

Your REGA tt... P6 had also pretty good reviews at the time, also in my mind a good match to your EAR, I'd keep also.
To go *noticeably* up in performance will set you back mega bucks!
I know, having gone up from a pretty nice modified entry PROJECT tt to my SME 10 with appropriate SME V tonearm.

That in my take will mean, looking at your MP200, yes.
Again I also know the MP50 (not 500, but very similar I'm told)
Given that, now you mention a Lyra Delos, LOMC... I'd say this in my estimate is shooting too high, as you other items I mentioned would pretty much immediately as for more upgrading to make the move work best for you, IMHO.
So what's the alternative to your MP 200 then?!? 
I suggest a very NICE MM cartridge, something better than an MP500 even. And NOT an e.g. Ortofon 2M Black and such either, I heard them, I'm not too impressed... 

This better could be some top of the range Audio Technica, more easily availble in your location?
If you can find a Garrot P77, I listen to one right now, and it beats my Ortofon Cadenza Black and Quintet Black MCs (to my ears), in fact if you make it a project, try and find a top NOS MM on the web, so long you sure to take undamaged delivery.
(No more to be trusted here in SA, you best know your situation I'd estimate). 

Lastly, if your PCM speakers have bi-wiring terminals, use a good single wire speaker cable, terminated preferably with cable shoes and connected to the BASS terminals!
Then make sure to replace any plated sheet metal jumpers with decent, short wire jumpers using also spade connectors most preferably. 

All that ought to make a difference to your listening experience for sure, IMHO. 

Let us know how it all goes, but the first and most imortant step would be a top MM cartridge, I'd say. 😉
M.