Geoff:
Surge brakes are cheaper for boat trailers.
I like electric brakes.
However, I have only ever seen them on larger boat trailers.
I mean the ones for boats close to 30'.
Electric brakes can be adjusted inside the cab as you know.
And you have a manual lever to apply them if/when needed to straighten things out if need be.
Also, when you unplug your lights at the ramp, you also unplug the brakes.
This makes backing things down the ramp easier.
Lots of advantages to electric brakes.
I would upgrade to electric.
I would also upgrade to disc brakes if your rig isn't already disc.
If you tow a lot of miles, brakes are worth every penny you spend on them.
Think of this.
Why do all old muscle car owners upgrade to large dual piston disc brakes on cars that originally used drum brakes?
What also so they go with stainless steel lines, etc.
They want to be able to control and stop that rocket.
I drove those cars back in the late 60's and 70's.
Stopping wasn't fun.
Good luck and keep us posted.
Afterwards get a 2 cylinder kicker.