Dan,
All of the major manufacturers have very reliable Multi Function Displays (MDF). As I understand the "Carbon" it is designed mostly for the fisherman, where you can have transitional sonar, CHIRP, Down Scan and Side Scan, without any additional "black boxes". Any of their standard type HDS displays will do the traditional sonar, Radar, and chart plotting. For engines which have NMEA 2000 output, they will also monitor all of the perimeters. (This goes back almost 10 years). Problem is that if you still have a 2005 Honda on your 22, then it will not interface with any of the MFD, and for an alaska trip, I would rather have two MDF, so you can watch: large scale chart and small scale chart, Radar and sonar (traditional depth finder). We cruised AK with our Cal 46 long before chart plotters were available--and even rarely used traditional depth finder (mostly when in uncharted areas, or some very narrow passages, with 6' draft).
The down scan, side scan and CHIRP, are good for certain types of fishing--and can also give some good information in anchorages, but for 99% of AK--not necessary...