Hi!
As LES mentioned, there are a few different ways to accomplish porting or braking. A brake is designed to help manage recoil and its affects. What are the ways to do this? It depends on what you want to accomplish...
If you want the look of the brake;
You can purchase a factory barrel,
purchase a clamp on device, or
you can have your barrel threaded for accu-choke (which is a specific thread cut to the inside of your barrels muzzle) You can get a brake that does or does not look like a breaching stand off device.
Either of those accomplish not only the functional aspect of a brake, but also provide that look. There is a cost asssociated with each, but the clamp on device is like the least expensive. Kings Armory makes them for sure, though I couldnt say if they make them for the 590A1's heavy wall barrel.
Porting, like what Vang Comp and Aimpro, are also effective at helping to control muzzle climb. I have the VCS porting on my 590A1 and am very satisfied with it and in fact have video posted here in the Product Review section so you can clearly see full powered loads being fired and their affects and how well behaved the gun is!