6# Hi-vis Crappie max is my go to line for all long-lining. I have a spool of 4# Hi-vis, but its to light for trolling stumps and standing timber. Use a meduim reel with larger spool and Magic-line spray and it will cut down on memory. I use Shimano IX 2000R's for my long lining setup.

Shimano IX Spinning Reel | Bass Pro Shops: The Best Hunting, Fishing, Camping & Outdoor Gear