Friends of mine just got the Lowrance iWAY 500C GPS with MP3 playback, and its 5" (diagonal) screen display is awesome! I'm thinking of replacing my 1.5 year old GeoSat2. Here's a link for more info:
http://www2.buydig.com/shop/product....sku=LRIWAY500C
If that doesn't work, try www2.buydig.com and search for Lowrance 500c. List price is $699, and their price is $595 with $100 rebate!