just bought a used 14ft Lowe with a 25 hp mercury from a friend bare nothing on it I had to build a. Trailer for the boat have to bye lights for boat and a battery the question is on a small budget ( wife wants to kill me over this boat lol) what is a good unit to find fish in a deep lake ( lake Huron ) and also work in a deep river something new or used I just wont to fish but still would like to have quality thank you