We've just bought a LG sound bar to go with our Samsung TV. Sounds brill.
Yes you will need another remote, the TV's remote will not operate the sound. The LG remote will turn the TV on and off and change chanels but you still would need the TV remote for the Guide etc.
The LG sound bar is bluetooth too and I play my laptop music through it.
"HDMI ARC (Audio Return Channel) allows you to easily connect compatible devices to process the TV’s audio signal without a separate optical cable to your receiver. Two HDMI inputs keep your AV devices connected with fewer cables for a totally new audio experience."
Thanks Ed, it's a UE42F5000, (42inch non smart LED)
I was thinking of getting a non Samsung one as they are not as expensive.
However I really don't want to have a separate remote for the volume, so I may have to reconsider.