Hi Magic. Welcome to the forum.
I think you have two options...
1) Sit next to your husband so you can see his depth finder (ugh! Sit next to your husband?! hehe)
2) Have him buy a second depth finder, mount the transducer on the opposite side of the boat from where his is mounted and mount the unit up front where you can see it.
There aren't any "dual display" depth finders that I'm aware of. Not within reach of a normal person's wages anyway. I'm not sure what kind of issues you may have with two finders conflicting and causing noise for each other. I think you would have to look at the operating frequency of the two units and make sure that they aren't running at the same frequency. Otherwise, both would pick up each others' sonar returns and cause problems.
Here's a little bit of information that I found using a google search:
Google Search wrote:Choose the right operating frequency for your sonar. High-frequency units show greater bottom and fish detail, but use a narrower sonar cone that does not penetrate to the depth that low-frequency units do. Unless you fish deep and large lakes, a medium- to high-frequency unit is your best choice.
Consider buying two depth finders, one mounted where you steer the boat and the other mounted where you sit to fish. The steering-area unit should be designed primarily to read the lake bottom for general structure and possible obstructions, while the other unit should deliver detailed images of the area you're fishing in.
I've never personally tried to put something like this together.
Good luck! Let us know how it goes!