Why are you only looking at full frame Sony bodies? Note that I’m not saying that’s a bad choice necessary, but what is your use case? You’re also going to want a quality lens or lenses and those will add more cost - especially for full frame.
If you’re coming at this from a purely budget perspective, an APS-C DSLR body probably makes the most sense.
I want the larger sensor, not least for night photography. I love the tone of Sony images. I want mirrorless. My current setup is an APS-C Canon system (70D). I have never loved it and want to switch.
When you say tone it’s worth mentioning that you’re probably talking about straight out of the camera JPEGs. I’ve used Nikon, Sony, and Fuji bodies over the years and their RAWs all look very comparable. I share your opinion on Sony’s straight out of the camera JPEGs, even if you and I might be outliers here. I find them to be fairly accurate/representative of the real world. My D40/D5300 were pretty accurate, but the Z6II was a bit warm (not that that’s unpleasant). Fuji is a bit too stylized, but was a bit more real world IME.
Do you care about AF performance? If yes, the A7III and A7III are where I would start. If not, walk back to the A7II/A7RII. I would personally skip the A7R as it lacks IBIS.