I just bought an Orbitsound A60 soundbar and subwoofer package. List price is £399 but dropped that to within your range when I bought it with other goods in CurrysPCWorld.
I spent ages trying out various Samsung, LG , Panasonic, Bose and Sonos equivalents, and the Orbitsound was IMHO the best even against much costlier options. I like the fact that it's made of wood (and British!) rather than plastic/metal and so not only is the sound much 'warmer' but there's no 'rattle' at high volumes.
With Dolby Atmos enabled output, the 'surround-sound' is terrific, particularly if you put bar in front of you and the sub behind where you're sitting!