Personally I think with that budget you’d be better sticking to a solid stereo amp, albeit one with a subwoofer output and ideally some sort of bass management so you can set the crossover. That’ll give you the extra welly for movies and will take a little of the strain from your amp and main speakers.
If you want good music performance from an AV receiver, it is possible, but the most renowned brands for music (Anthem, Arcam & NAD) are pretty expensive.
Each option has its own pros and cons, so you whichever you choose, you just need to have your eyes open.
2 channel won’t typically have the flexibility of an AVR, so you won’t be able to tweak the settings for the dialogue for example. My own AVR can flip between 2.0, 2.1 & 5.1 on the fly so I can squeeze the best from whatever source I’m watching/listening to. But a solid 2 channel system can sound great for TV viewing, especially the BBC which only broadcasts in 2 channel anyway.
But for really satisfying musical performance, AVR’s will be around £2.5k and up. And as AV receivers are pretty expensive right now, they’re not particularly good value.
So at your budget, I’d stick to 2-channel. Just be content with the things it won’t be able to do, but revel in its 2-channel performance.
Can I ask, what’s the size of your room?
So you have a preference for standmounted speakers or floorstanders?
Have you heard any systems yet that you like the sound of?
Please don’t pull the trigger based on our recommendations. Please make sure you demo first.