1) get the cheapest surround processor with the features you care about. If you don't need room correction, then an older unit will be great. If you need room correction, don't worry about 4k processing. Just run your source to your TV. Get the connections you want. Don't worry about whether it supports DSD/MQA/whatever digital audio because...
2) Get a separate DAC or even a DAC/Streamer with a built in preamp. For price/performance it's tough to beat the Mytek brooklyn or the Benchmark DAC 3. I recommend a separate DAC because digital audio is changing quite a bit now too. That being said, this will be *fine* for almost all the audio you want to listen to.
3) McIntosh amps are solid pieces of kit. Good quality, good resale, and (a little embarrassed) they look good, too.
4) Get the best speakers you can get. I'm not a believer in expensive cables. I'm a physicist...so you'll have a hard time convincing me that one piece of copper (or silver) is better as a medium for transporting electrons than another. As long as it's properly shielded, you're good to go. Don't spend thousands on cables.
5) If you have money left over, *then* look at nice stereo preamps, but after you pick the speakers/amp you want. That will dictate output voltages and give you an idea of what works *in your system*.
I actually started with the speakers. Bang & Olufsen BL5s. Ended up with the Emotiva XMC-1 (none of the upgrades), and since I didn't need an amp, and I'm just using monoprice cables from Amazon, I had cash, so I stupidly lost my mind, blew my budget, and got a ARC Ref 6. I had a nice CD player (BS9000) and just purchased an NAD M50.2 for streaming and digitizing my CD collection. The only thing I'm debating now is whether to get a new DAC for the new digital formats, but I'm thinking the built in dac on my processor is fine.