I've use both 40# mono and 50# power pro, currently using power pro as it's much softer than the mono, 10' or so and change it every few weeks, my 2 year old wire still looks brand new and I can break my rods down without worry.
Best bet is to call your guide and see what they recommend or talk to a guide/local shop on the river system you're fishing. The fisheries and regulations up there vary more than anywhere I've ever seen.