RuffWear has some very nice dog coats, harnesses, and packs.
You probably already know this, but in case someone doesn't: when just walking around, it would not be cool to use a vest that has any kind of SAR identification on it, even on a dog that is trained for SAR.
Actually, the Ruffwear looks almost like what I seen. There was a show on discovery, where there was this hiking couple. They were in the Canadian Shield, through the woods and canoeing, etc. They had a harness that had a pack attachment. There was a handle towards the middle that assisted in lifting the dog around different things. The pack was small, held two water bottles, one of each side. They said it was a SAR harness with pack vest. They also said where they got it, they got his name embroidered for free across the chest.