I'm in the same situation, here is what I'm lookin at,
Lowrance 527c DF Igps
Or Lowrance 339c DF Igps
Both these units are color, dual freq transducer,and Internal GPS Antenna, and also 4000watts of power. They both are around $699 with the skimmer transducer.They also allow for the Hot Spots or Avionics chips. If you are a KBF member you can get a GOOD discount thru them.Go to Lowrance.com and you can compare the differrent units.