It's a bartop. Any AC fed garbage bin special is going to work just fine, although USB powered speakers are less of a hassle.
I can absolutely vouch for the quality of the S150. They aren't terrific, but I think we already suspected as much. Solid sound quality in a small package. A sound bar may be a simpler option, but I know nothing about how they sound.
As for naked "bartop cones", I wouldn't recommend them. Those are generally cheaply made, require separate amps (cheap ones can sound like crap, good ones cost like some half passable PC speakers, which defeats the purpose) and may mess up you stuff with their magnets. Avoid if possible.