There was a post here about a 5v power supply for TinyG. Unfortunately this topic got deleted when we were fighting link spammers who have attacked our site.
The short answer is yes, the Meanwells are great supply's for TinyG. The 5v is overkill (as you suggest), but should work well. We don't have a case for TinyG, but check out what some people have been doing on the Shapeoko forum.
-Alden