My friend wants to buy two 999ci hd si unit to put on his console and trolling motor. He is asking me what all he needs to do this. Can someone tell me what cable he will need to connect the two units together for Ethernet and what trolling motor transducer mount he will need. He also wants to put the lakemaster card in the unit. Does he need to put a card in each unit or can he just use one to use both units. I know the 999 has been out for a while is there any newer units for about the same price that are better? Is there a combination deal anywhere where he could buy everything he needs together? thanks