Wow those Dali Oberon 9's are some seriously big speakers! If it's just music, I am not sure you'll need a sub with them, they are going to move a lot of air on their own. For movies, sure, there are a lot of sound affects designed just for subwoofers.
Start with the speakers you want - put most of your money into that. The speakers make all the difference, it's the only thing that actually makes sound. Unless you like listening loud, there are a lot of amps that will power those speakers no problem with their 90.5dB sensitivity. I mean, pick any amp mentioned in this thread and you're good. Do they all sound a little different? Yes. Will some sound better than others? Yes. Does it matter compared to the speakers and room placement/treatment? No.
If you like cool retro looks like that JBL amp you can always just buy an actual vintage amplifier. Sure, they might hum a bit and throw off a lot of heat, and they won't measure as well as a modern amp, but they will look cool for sure and you'll get plenty of power for the low end.
You do need to think carefully about how you're going to serve up music to your amp. I would get a dedicated device for serving music rather than something built into the amp, because those standards are always changing but good amps are forever. You don't want to have to change your amp in five years because there is some new Wifi standard or everyone starts using some kind of new app it doesn't support. So put some thought into that.