if you have a BPS, Cabela's, GM, ....ect close by

go there and check out all the different models from different companies. Play with each(make sure you have a few hours to) the one you think you like now, might not be that way when you look at them. I did this when I bought my last one, was really a good idea. the one I had my heart set on, I didn't get. tried another that I thouht was eiser to use.

i would go with the lowrance x-135, its got 480x480 pixel , 4000 watts. thats probley the best unit for the money but its a little bit over $300

http://www.basspro.com/servlet/catalog.TextId?hvarTextId=52516&hvarTarget=search&cmCat=SearchResults