Forget Fluro, not worth the money for making guards.
Have a look at some of the carp "stiff rig" lines as these retain there shape well when curved to make the guard.
For the standard loop guard I use ESP Stiff Bristle in 9 kg and for what I call the Dracula guard I use the same stuff in 11kg or the Daiwa Metomorphic Stiff Rig line in 30lb