My stalking/beating/everything smock, the Liatach smock (modified). Size wise I found them quite generous, but them I'm quite slim.
If you're anywhere near our neck of the woods, it's worth visiting them, as they will add pockets, sleeve length, exetend the back etc, basically anything to your spec. Youi can also get a feel for whether you want single or double Ventile, lining etc.