I see this is your first post so welcome to NAFFF. I hope you become one of our active members. We all like to share experiences and would be interested in how your outfit works.
A lot of people use medium action rods for nymphing but I prefer a little faster rod. The SA and Rio nymph lines are very good for this type of fishing. These nymph lines are weight forward lines. They are a little larger in the front diameter for better flotation. They also have a long head that helps with mending.
Ard's suggestion of a double taper would be a good line also. I would go with a standard weight double taper line for your rod.
SA Nymph Line.
• Optimized for high floatation in nymphing conditions
• Commanding front taper to handle all types of nymphs
• Taper designed to handle split shot, strike indicators and droppers
• Excels in big water and roll casting
• Powerful front taper for better control
• Great for single hand spey type casts
• Orange indicator tip