I'm still using my old Sony 1080p 40v4000 for now. I bought it over 7 years ago for £400 and while it's now a little dated, 1080p still looks absolutely stunning. I'm hoping whatever I go for next will be as good and last as long as this has. Absolutely brilliant TV, if the bezel wasn't so chunky I'd be tempted to keep using it. I'll be looking to upgrade probably just in time for Christmas to a 55". If I can squeeze the extra cash from elsewhere I'll maybe go for one of the OLED LG's.
Your Dad has the 650. Good choice

Yeah, you really need to update that TV. IT doesn't have ARC functionality, which is great. And I recommend going OLED!! Amazing TVs. Bought one last Christmas. It's what I am using with the K650. I have a Pioneer Kuro LX5090 in my movie room. The LG is better and I wasn't expecting it to be.
Don't know what your budget is, but you might consider the Philips Fidelio B5. Good looking soundbar and has a neat trick. The ends of the sound bar can be detached and become blue tooth speakers that you can place as rear speakers
