Ok looks like you have the same bar as Old Tony and i know for a fact he is using an aldi winch so it wont matter what winch you choose it will fit your bar.
The winch is really easy to fit as FB said you will need a extra set of hands, so unless you were born in Alabama you will need a mates help.
I run a 1200lb winch and i dont have a dual battery.
Even if my car had busted and wasnt running, a good battery will get you at least 1 long line recovery before it got lazy.
So in my opinion a dual battery is not an absolute must for having a winch.
Size of the winch will depend on what you tend to pull with it, if you load the heck out of the ute and have a big van or camp trailer it is prob best to go bigger then 9000lb but its not an absolute must, i have seen patrols and cruisers with 900lb winches and they worked ok.
I just think it not as hard on the winch if it is meant for heavier work then flogging the smaller unit, only my opinion though.
As for rope or cable i chose rope for a number of reasons like,
its much lighter, about 8kg in fact
,
its allot easier to handle,
it doesnt retain a memory like cable,
it will float,
when and if it breaks it is allot safer way less chance of the rope swinging through the air and hitting something or someone,
you wont end up with your hands torn open by a frayed cable.
If it did break you can get away with tying a knot in it or splice it like a ski rope to get you out of trouble, try doing that with a cable,
it wont rust,
it wont kink,
less maintenance,
fairlead has no rollers as its just a block of alloy,
It is actually stronger compared to the same thickness of cable,
The down side it has less friction resistance over sharp rocky ground, But with a bit of thinking you can minimise this.
Cable is cheaper,
some winches get to hot from the braking system and can only use cable as the rope will melt.
If you want to see how to fit a winch go to the TIGERZ11 web site and look at the video section, it has three videos showing how to install and how the cables need to be wired up.
Hope that gives you some ideas.