Caporegime
Op I suggest you go have a demo of a soundbar and budget system, listen to CD in stereo and movies
This site has mostly people happily spending £2000 on GPUs and just buy cheapest **** Logitech speakers.
If you bought that £450 wharfedale setup you could add or replace parts as needed, also in case of failure..
If you bought Sonos soundbar you have match it with their sub.
If I gave you a couple of PSA 21" subwoofers you wouldn't be able to them with the Sonos. If your TV lacks DTS out you wouldn't be able to use e-arc DTS.
Soundbars are better than built in flat panel but I'd rather recommend a t amp and some regular wall mount speakers rather than a soundbar.
That Samsung won't have 700w total power output not a chance. It'll be the usual overblown figures with high distortion
My advice...
A good modern Atmos soundbar is great at the price point - they normally just plug in to your TV and after a few calibrations from an app on your phone or front panel, you have a nicely setup system for your room. It doesn't come with a CD player as the above post might suggest. This would be yet more additional equipment, if you'd ever use your TV setup to play CDs at all!?
The £450 Wharfdale speaker setup would also require an AV receiver, cables, speaker stands and to be setup correctly in your own living room for it to sound good.
The Sonos rear speakers and Sub get very good reviews too and their wireless (it's a new thing)...should you actually feel the need for them.
If someone ever gave me a pair of PSA 21" subwoofers I'd sell them and keep the £3k+ for hookers and charlie (not really dear, honest). I certainly wouldn't be paring them with anything I'd ever buy for my living room. If I had a full blown theatre I'd still be using something else to be honest.
The LG OLED range at this time doesn't support DTS but will again this year. IF your source material is from around the time of Shakespear and only comes in DTS (is that actually a thing at all?) and still want it in surround sound, then just plug said CD player, thingy, whatever straight into the Sonos as it covers all the mainstream formats.
Soundbars negate the need for cable runs and turning your living room into a gallery for odd looking wooden boxes. Of course you can get better sound quality, but just like a better viewing experience it'll cost you.
If you like your living room to have a certain 80s student digs vibe then by all means go for wall mount speakers ^^ and don't forget to chisel out all those lovely cable runs for them right through that lovely 70s paisley/flock wallpaper that you just know will come back into fashion.
If you want 700w in your living room I suggest you call Everest first, then the police and fire brigade as likely outcome will look like a gas leak.
I thank you.