Buying into TV’s at the moment is a bit of a nightmare! It’s no longer about mainly just size and brand… You’ve got levels of peak HDR brightness to think about 500nits,1000 nits, 2500nits etc; the type of HDR supported ( HDR10 - Industry standard, Dolby Vision- Dynamic HDR, HLG - Broadcast HDR) < All of those in one would be great although Samsung are working on bringing HDR10+ (Dynamic HDR) Each scene is treated itself, rather than right now the metadata is from the film as a whole (Overall dark film means bright parts won’t be as good, and vice versa)
As far as the soundbar goes, the one I have is fantastic bang for buck (those Dolby Atmos ones are a bit too pricey) the added rear speakers are wired, but only to the wireless base. You can sometimes hear a slight hiss from them if you’re watching something with no surround, but nothing too serious, if anything just toggle them off via the soundbar Using it is a piece of cake if your TV has ARC (Audio-Return Channel) that way everything plugged into the TV will come out of it.
I realise now that I’m answering one of your first questions last haha. I only own one DVD (Spaced Collection) However, I gave my older 4K TV (Non UHD-Premium Certified) to my mother, she’s been watching NCIS DVD’s via a 4K Upscale Blu Ray player and it does an incredible job