G'day mate,
For mine i would go 6lb Rapala titanium braid, thats what i use or 4lb fireline with a 6lb Nitlon flurocarbon trace. That line can handle more than you would imagine, i have landed 65cm kings, salmon and big flatties on it, the key is when fishing light is to take your time and be patient.
BTW the fireline breaks above its rating.
Nitlon is about $17.50 for 100m as compared to vanish that is $19 for 200m or something, and i haven't found that there is that much difference between the two.
It can be expensive when fishing with this line so the key is to leave a gap on the spool so you dont get wind knots, its painful and time consuming trust me!
I fish the flats so my fish dont graze the flurocarbon as much as they would if i were in the boat so if fishing for bigger flatties i would go about 10-12lb flurocarbon, of course they can still break it but your a better chance with that over the the 6lb.
Hope that helps.