I'm going up to Lake Willoughby for a couple days and I know the place is known for its lake trout. I'm fishing braid with a fluorocarbon leader, but the question is what pound test do I need? I got some 20lb at the local shop because that's all they had but then went out later and got some 12lb. Which should I use? Does it matter a whole lot or would I have measurably better success with one versus the other. 

Sorry this post is here twice. I put it on the line, reels, and tackle section too and it got moved back. 

What kind of fishing for lakers are you doing? Trolling, casting, vertical jigging? I mostly vertically jig for deep water lakers and find that 8# test Fireline Crystal with a fluorocarbon leader works extremely well. And I'm using jigs up to 1 1/2 oz.. No problems, no worries.