hds 5 sonar/gps
hds 5x sonar
hds 5m gps (chartplotter)

Both the 5 and 5x will work with structure scan. Insofar as the mapping, it would be a personal choice. Many people opt to get the basic mapping and IF they need to take it a step further they get a card that covers the region they live in (hot maps).

My take...they are not currently selling a lot of the units with insight thus the $50 rebate. Insight, my interpretation, would benefit people along coastal waters, big lakes, etc. For me its just not feasible due to my location.