Eagle an Lowrance are the same companies like GMC and Chevy. The only difference are Eagles run a little cheaper but my advice for you is is to look at the 520 series from lowrance they are in your price range they have a 520,
522, 525, an a 527 I think the 525 and 527 have internal gps receivers I know that the 527 is internal cause I have one, it cuts down on on the issues with a puck and the unit is the top of that series and runs about $700. I would suggest to also buy a ram mount and a navionics premium chip too they are awesome and if you buy the ram mount if no one steals it, it will the the last one you'll ever buy. All the should run around $800 depends on if you buy the 07 premium of the 08.