Unfortunately, there isn't any Ginga english dubbed but you can find it with english subtitles, both GNG and GDW. You can find many volumes of the mangas translated by some online teams around (Ginga Scans to say one) but you can't find any traslated in the shops around. If I'm not mistaken, a company in the US began to publish the manga translated (GDW only) but it lasted only for a couple of volumes.
As for a first time watcher, it depends. If you're into violence and dogs, go ahead. I wasn't really into violence but I liked dogs and so, I ended up enjoying it now violence doesn't bothers me on manga/anime but at that time, I managed to watch without hating it, on the opposite.
Beware though...awful animation awaits you on GDW :'D