I use an #8 rod, floating line and 10lb leader, I have gone back to Copolymer as its a gnats thinner than fluorocarbon. One small tip is first you fire out a few biscuits to get the carp going, then cast out your "fly" then put out more biscuits around the fly but remember to leave some slack line if you lay your rod down while catapulting out biscuits. The reason being that carp will be conditioned to taking biscuits quickly once they hit the water so if your fly is there already you will get more takes. Another thing is if your fire out your biscuits HIGH in the air they land with more of a plop which really gets the carp interested. If you tie your own flies look here :
Success of the ?Ginger Minger?
Use Sweetcorn if they dont allow dog biscuits and a yellow fly, or bread and white fly, they both work.
Good luck