I wouldn't mess with Down riggers . You can use Jet divers, Dipsys , In line weights , Lead core ,snap weights, or bottom bouncers to get your lure into the strike zone. Do alot of reading and asking questions to experienced fisherman , costs add up quick when rigging a boat. Make sure you get all the safety gear you need first . Alot of different ideas to consider. I would say you will need either planner boards or in line boards. I use both types depending on the number of rods and type of lures being used. have four down riggers and only use two when Salmon fishing .good luck