[Mart]

Olguy, whether the dual setup is "safer" is a moot point. This is due to it not being designed for a dual setup from the factory. There MAY or MAY NOT be enough extra travel available to make the brakes work if one side fails.
You also have to factor in cylinder diameters, and the fact that the dual setup MAY need residual pressure valves to be fitted. All this extra plumbing creates plenty of extra potential leak paths.
In my opinion, the better approach is to make sure your existing setup is maintained in tip top condition, including making sure the emergency brake is fully functioning and properly adjusted.
By asking for help you lay yourself open to all sorts of suggestions from all sorts of people. But in my opinion, as an engineer in the auto industry for 45 years, I do not believe the swap to a dual master cylinder, in an application that wasn't designed for it in the first place, is not necessarily any safer. It MIGHT be, but how can you tell?
You would have to set up the dual circuit cylinder setup and then induce a failure and test in on the road conditions, measuring stopping distances.
I don't know anyone that has actually done that.
If you don't want a lot of work, the work you do might be best targeted at making sure what you have is tip top. Inspect the level regularly and drive with confidence.
I am currently building a 32 sedan. It had a dual circuit master cylinder in it and I converted it to a single. I mention this so you don't think I am just a keyboard warrior and I am prepared to put my money where my mouth is.
Mart.