Hey grislybutter,
Don't avoided the word "SYNERGY", it's really prevalent in audio, & essential for putting together a system/package. For you, the days of having a really good system based on having a good pair of speakers are gone. Finito.
Getting back to synergy, a friend had this KILLER system on paper, but his big buck M/C Benz Micro cartridge was picking up FM signals & nobody had a reason why. (Back to the drawing board).
The main thing Gris is not to get frustrated. You've gone from a 70's receiver, to a nice dual mono Integrated Amp, with separate power supplies & output transformers. You are in a state of metamorphosis & your ears don't know what to do with it.
This is actually a good thing, except it's going to cost you money, LOL. You now have a small Porsche engine (Musical Fidelity A3.2), which you're operating on Wal-Mart tires (your speakers).
Pretty hard to recommend a speaker when I know nothing about your room .... floor standers, book shelves, etc.
But if you're set on warm sounding speakers, you may want to consider vintage speakers, AR's, or Advents. Might want to look into ESS. Problem is they're collectability. They've gone from "get those old things out of here", to being double, triple, of their original price. And who knows what they've been through. IMHO, when you can get a pair of Paradigm monitor 9-v1's for under $500 CDN dollars, it's really hard to justify $1200 dollars for a pair of AR3's that sold for $95 bucks in 1975.
The worm has turned Gris & there's no turning back.
As for recordings, Acoustic Sounds, Inc is a good place to start.
https://store.acousticsounds.com/cat/5/Vinyl_Record