Have a look here. WhatHiFi does Best Buys per budget band. https://www.whathifi.com/best-buys/home-cinema/best-home-cinema-amplifiers https://www.whathifi.com/best-buys/home-cinema They also have forums with lots of enthusiasts to answer questions/offer advice. Another good place to ask questions: https://www.avforums.com/forums/ These are very active.
That's where I'm not sure how best to proceed. I could work with a budget of around 900-1k for a decent home cinema system (excl TV).
Then you need a budget. There's so much choice it's ridiculous (y)
Multi-channel ideally for film content. Some music albums are mixed in surround-sound, however, most are mixed for a stereo mix (to be converted to MP3 for spotify on to Dr Beats headphones).
Stereo only? The Yamaha R-N602 is decent for what you say.