Um we already have that branch.
Its called the Bureaucracy.
Pick up any 1st year college government book. It will describe the 4 main "branches"
Leg, Exe, Jud, and Bureaucracy.
Then factor in that both the Executive and the Legislative already have what you are talking about, and you are in a serious case of redundency.
The GAO was mentioned. It is basically AWSOME.
You could also google "regulatory agency". There are long lists.
FCC, FEC, etc, etc.
In addition, you could easily find all the information you are looking for, in terms of failed gov programs.
http://query.nytimes.com/gst/fullpag...52C1A963958260
Here is a good one I reference frequently.
Ixtellor