Transducer Suggestions

[Surfnski]

Anybody know what options I have for a direct replacement of the below pictured transducer? I've been looking at the lowrance HDS stuff but I'm not sure that the transducer will fit properly. Any suggestions on what to go with? I'd like to do the install myself but I want to make sure I'm using the right parts before I start ordering anything.

Thanks!

Click on the image for larger pic.