PHP Warning: Use of undefined constant VBA_SCRIPT - assumed 'VBA_SCRIPT' (this will throw an Error in a future version of PHP) in ..../includes/functions_navigation.php(802) : eval()'d code on line 1 Line and leader for flathead.
I generally use 4lb fireline but if you're just chasing flatties I'd go for 6 or 8lb. Then for the leader, 12lb linesystem fluorocarbon (made in japan) is great stuff, which I get for about $12 per 30m roll. Seaguar leader is also good as Neil mentioned.
I agree with the other guys, I use 6lb fireline and 12lb leader, this will handle all your flatties. Just don't let them get their head above water you they can thrash from side to side and, as you are landbased, just walk backwards to beach them and you won't have any troubles.