I am buying a ultrex next week but I need some help from y’all first. 20ft Basscat Pantera 4 is the boat. My questions are , what shaft length should I go with and 24 or 36 volt? Also where is the best place to purchase one? I will be using it for spyder rigging but I do bass fish also is the main reason for the ultrex. Any help would be appreciated.