I am looking for some H-E-A-V-Y fluoro, 40-55lb test. I don't need much. Who makes the most invisible fluoro? I need it for leader material. Thanks!

Triple Fish, Seaguar, Maxima....

You are looking for Saltwater Fluoro Leaders: http://triplefishusa.com/store/index.php?act=viewCat&catId=29

Leader line fluro or not is a bit more difficult than line of the same test to get a good knot, keep tieing it until it's perfect. 3-5 wraps on a clinch knot will darn near anything. Of the fluoros I've tried I prefer Vanish, price is right and I like the way it knots, I use 40#. I only go this heavy fishing ocean offshore. The rare times I use 60# or 80# I crimp instead of tie.