A big thanks to everyone for sharing their opinions, which interestingly varied quite a bit.
“The phono stage to the preamp [as closer to the source is most important]” - 2+ votes
”The preamp to the power amp [because everything goes through that ic]” - 2+ votes
”They are both important but start with the speaker cables and work you way up backwards”
Spend, in essence, $970 on one and $30 on the other, with at least minimum quality (eg a Mogami cable from WBC) “so you can upgrade the second one later and thus end up with two great ic’s”
“Have you considered upgrading your cartridge” - this was an interesting one, as it didn’t address the question but, hey, that’s always a possibility at some point
So, I ended up buying three different pairs of ic’s and one pair of speaker cables, to play around with…:
XLR ICs:
Townsend Audio DCT 300
Wireworld Equinox 8
Vogue Audio Silver Strand Ultra
Speaker cable:
Harmonic Technology Pro-9+
(all purchased used from various places - mainly USAM - in very good condition)
So, plenty to play around with in different places in my audio chain…
How much fun, and thanks again for everyone‘s input!