I would love some suggestions on great acoustic...

seu jorge doing david bowie covers in portuguese, found on the soundtrack of "the life aquatic". all acoustic, all bowie covers. awesome

Granny- try Kaki King for a very different type of acoustic guitar. Definitely not flowing but quite intriguing I think.

Colin Meloy "Sings Live!" (The Decemberists). This is one fantastic sounding lp! I fear it went under the radar, so here you go. (If it's still available). As I recall, I ordered mine direct from Jealous Butcher Records at a great price.

Jack Johnson? I got a cdr so I don't know which album it is but I really like it. If you are in that Van the Man camp I think you might like Jack Johnson.

I saw Gordon Lightfoot live in San Francisco the other night and I'm reminded how much I like his music. What a great body of work! Your description of "flowing and melodic" is his style in a nutshell.