There are a lot of Skagit lines that will work with your rod. Without knowing what you are fishing with and for, how skilled you are or how you like to cast, it is nearly impossible to tell you what would work best.
I would imagine that your rod should handle somewhere between 450 - 550 grain line. Most guys that I know, try many lines to get what works best for their casting style and rod. Many decent tackle shops have lines that they will let you try out. I even recall one tackle shop have a "Spey Day" get together quite frequently on the river for people to demo rods and line. I've found that Skagit Short or Compact is pretty decent for big flies and like a 480 or 510 gr line should match your rod.
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