BrakeSmart, Hensley Arrow and Hypowered Disc brakes
If you want the safest combination that works extremely well together than go for a BrakeSmart controller with disc brakes. If you are getting a new Airstream you can have the brakes factory installed. The BrakeSmart will work with 1, 2, or 3 axles and will automatically sense how many axles or if an electro over hydraulic brake actuator is present. You will not have to touch the brake controller. I have had several controllers and until I got the BrakeSmart I used a Jordan, which is really good but not nearly as good as the BrakeSmart. I just put another BrakeSmart on my new Suburban.
Hensley is the safest setup and it works. It installs in 4 to 6 hours, but I would plan on a full day, because you will want to figure out how this beast works.
All of this stuff is expensive, more expensive than the other solutions that get the job done. But safety is an insurance policy that is expensive because those who pursue safety don't ever need it.