Nice,we use that ,15# maxima mono also.When trolling cranks we use size 2 dual lock snaps.The snaps give the crank the freedom to move properly.Just make sure when you put the crank on the snap make sure the the point of the snap is facing upward.For years I didn't realize it made a difference,but if that point faces down toward the lip of the crank, it will scratch in a semimoon shape on the lip of your crank and inhibit movement.
Now,if you want to make a leader for using a spoon or harness off a dipsey,we use 20# seaguar flourocarbon at 7ft, with swivel on one end and snap on other.