You can buy cheap and save a couple dozen dollars, but frankly I agree with MS - get marine rated panels from a known source (Kyocera for me).
Some of those cheaper ones are made for home application - they put out 30+ volts and are meant to be wired together for that use (I've sourced cheap, then threw out the idea).
I hear you say you need 60-80. Get a 125w if you have space. You can never have too much power/charging ability. You'll also see that the bigger the panel the more watts to the buck are common.
Here's a good link that shows that.
Solar Panels at Affordable Prices