There are literally tons to choose from. I prefer side discharge style brakes myself. For my rigs I have been building my own with great success. I have heard great things about the "Muscle" Brakes, but there are many good brands out there, this is the basic style I prefer. Here's a link that may be of help:

http://www.centershotrifles.com/prod...zle_brakes.php

The radial type brakes work well also, but if you are ever going to shoot prone or resting off a log/tree for a shot at a deer the radial type will try to blow up dirt/sand right in your face. However off the bench the radial types work pretty well and don't seem to blast the shooters to your sides quite as bad.