sonar options question

I have two very out-dated sonar units on my 2000 Alumacraft Tourn. Pro: a Lowrance on the dash that doesn't do anything for me as far as identifying fish, but does track the depth well; and a Bottom Line with the ducer mounted to my trolling motor that goes berzerk after I use it for a few hours and loses all ability to track depth or fish.

I just got a good deal on a Lowrance X510C, and plan to replace the Lowrance unit on my dash with that one.

I want to put something new on the bow, but I want to get the most bang for my buck and I'm not crazy about another trolling motor mounted ducer. Are there any options out there that I am overlooking?

In the catalog that I got with the X510C it talks about a switchbox or something of that sort that allows (if I am reading it right) two sonars to run off of one ducer; is this for real, and has anyone had any experience with this setup?

Could I put something like a Lowrance X67c or similar color unit on the bow and run it off the same ducer as the back one, or I am completely screwed up on this deal?

[Wall@y@]

Yes there is a switch that will allow you to use your 510 unit with other Lowrance units. Go to LEI Extras and there are two switches to choose from. One switch unit is SB-10BL part #46-27 and the other is SB-9BL part #46-26. These units are compatible with with your sonar unit.