I do recommend that you use intermediate or sinking line, whichever allows you to retrieve your fly while keeping it just off the bottom, where fluke lay to ambush prey. If you are new to fly fishing, note that full sinking lines are rated by grains, the higher the number, the faster it will sink.
A standard 9 ft fluorocarbon leader, 12-20 lbs should is enough for most fluke you’ll find, but remember they have sharp teeth so be ready to adjust your setup depending on whats lurking near you.