baboos_boat and all,
First I think maybe I'll change the name that shows up over in the left column of the posts...seeing my name so often everywhere else is embarrasing!

While I appreciate the kudos, the reality is that I am
not the only person out there capable of putting a C-Dory together or recommending electronics. :shock: My desire is to share what experience I have with folks so that
they have more information available and can make their own decision. I do get to see an awfully lot of different installations and have used most of what's avialable to the small boat owner and I try to pass that along.
I do not "recommend" the Raymarine system; it's simply one of the choices available on the market. It isn't "better" than the Garmin products; just different. Garmin doesn't offer a fully "integrated" system (GPS/Chartplotter/Sounder/Radar) so if your inclination is toward a fully integrated system you'll not be considering Garmin. Many folks today are interested in what a fully integrated system has to offer and that leads to the logical choice of either the Raymarine HSB system or the Furuno NavNet system.
So the first major decision in my book is to figure out what 'level' of system you want; a fully integrated system, partially integrated system or standalone components. There are valid reason (money notwithstanding) for choosing each of them.
You have to examine your own preferences and use scenario to figure out what makes sense. Some folks are happy with a nice 'boombox' stereo system; others won't accept anything less than the highest quality speakers, tuners, amplifiers and such...most of us end up somewhere in between. [Different strokes for different folks comes to mind.]
Nobody "needs" (unless you're a commercial operator making your living) a fully integrated nav system, an autopilot or even a GPS, chartplotter or sounder; we don't even "need" the darn boat!

Really it's about pleasure (they're pleasure boats, after all) and you should put the thing together the way that makes
you happy. Some folks aren't happy unless the boat looks like a 747 cockpit; others want a depth sounder and a VHF...period. You choose.
If you want superb navigation, nobody does it better that Garmin; I've installed more 188C units than anything else (some 2006C's and even the 2010C's too). There are many other really good units out there too, so you've got lots of choices. The 188C is nice since it's got the sounder built-in but if having a full-screen, always available depth sounder is part of your requirement you could choose the 182C (same beast as the 188C without the built-in sounder) and get a separate depth sounder. The 2006C and 2010C need the GSD-20 sounder module added to get the sounder capability.
Want a radar that's not part of the main display; there are good standalone radars out there (and some not so great too). You could use a Garmin 188C for GPS/Chartplotter/Sounder functions and have a separate radar unit (this is the 'partially integrated' system).
And, of course, you could have a separate unit for each of the functions you want. In a CD22 that tends to get pretty tight but it's been done and been done often. Most of those choices were made when the multi-function units were not available.
There is no
one answer in making the electronics decision; there is also no
one answer in powering a CD22. If I put you in a room blindfolded with a every major brand of motor (of the appropriate size) in there you couldn't make a bad pick. You can make better picks based on your own personal use and preferences. Where's a good dealer? What brand do they carry? Where do you use your boat? Water conditions? Altitude? Typical load? Typical trip length? And on, and on.
If you're looking at twin Honda engines don't sweat the choice between the BF40 and BF50; buy what makes you smile when you see them hanging on the back of your boat (doggone it, it's a pleasure boat; we're not 'justifying' our decisions on a corporate basis). In reality there isn't enough difference in performance to amount to a hill of beans; everyone I know that has either one is happy. If you want extra horsepower "just because" then, by golly, get it. I just don't buy into the argument that it's "needed"; there are too many CD22's out there with twin 40's to make that a valid argument. It's different if it just makes you happy to have them; that's the most valid argument I can think of. You don't want to be out there running around with 40's wishing you had installed the 50's every time you run the boat. Until this year there was about $1500 dollars (or more) difference in going with the 50's versus the 40's and most folks choose to save the money since the 40's do well. Now the margin isn't as wide we may see more 50's going on...just because (mostly just because it didn't cost that much more :wink ).
I've typed too much...