Bernie already has electric brakes, to change to hydraulic brakes is a reasonably big job.
Some of the American systems use a decelerometer in a trailer mounted device that also has an over ride and sensitivity control that connects via Blue Tooth. The problem with those, the yanks use very strange trailer plugs ....
The better alternative might be one of these
https://www.trailersrus.com.au/electric ... leader-cab and an old smart phone, doesn't need to be on a network, it uses the Bluetooth function
Here is a PDF on how to install one
https://www.trailersrus.com.au/assets/b ... 000-PS.pdf
Doesn't look too complicated and a trailer breakaway can be added in to allow an uprating rather than derating the trailer capacity
T1 Terry