There is a Region 1 edition of Sherrybaby. This was released by Screen Media/Universal in January 2007, and is almost identical to the Madman edition.
The US release features the addition of English and Spanish subtitles. It also presents the film in an aspect ratio of 1.78:1, which is slightly off the correct ratio of 1.85:1. The only extra on both editions is the theatrical trailer.
My advice would be to buy the edition which is more convenient to your location.