Remember, just buy what YOU need. Granted on a yak, you don't NEED a color high resolution fish finder or mapping GPS unit (I felt those features were important to me, and would stand up to the saltwater environment where I predominately fish). Having seperate units IS an advantage when you want to utilize your GPS in the car, hiking, biking, or whatever. But most likely a GPS for under $200 will not have the features one would want when driving (i.e. a color screen, higher resolution, mapping functions, etc).
Garmin does make some AWESOME units, but the ones you mentioned do not have similar features/characteristics as the Lowrance unit previously mentioned above. In addition, what GPS are you describing that will only cost $150? Will it be able to show maps (as a basic map already stored or otherwise)? I don't want to sound argumentative, but those two units (although would cost less than $399), would not provide him with the same features or qualities, except for having a seperate handheld base model GPS. But if doesn't need or want those features, then my points are moot.[wink]
Good luck with whatever you decide. And whatever choice you make is ultimately the right choice FOR YOU![grin]