Hi James
Welcome to the world of Alcans, Alwests and their other cousins.
Whatever your question, likely one of the regular contributors to this website can answer it.
David (our webmaster) is having some rather complicated issues with posting website updates. Typically we have a fairly regular flow of new info in addition to the Forum. Hopefully he will get this sorted out eventually.
Re “finding one to fix up” . . . . this is pretty much the only alternative, given that all of these boats are over 35 years old !
I have never heard of an Alcan or Alwest 370 with a single engine. These can be a handful to maneuver even with twins. I have seen 32s with a single engine and have heard that some 37s cruise on one engine to save fuel. For 15 years I have been planning to do an accurate mileage calculation but have never done so. Maybe I just don’t want to know! I “think” we are running about 3 to 4 litres (1 gal) per nautical mile at our usual 7 knot cruising speed.
We boat in the St Lawrence and Kingston area. Many times we have been in 4 ft waves that are starting to throw the dishes about in the cupboards. I have only felt “threatened” one time out in front of Kingston in 6 ft plus waves. This is partly because the wave peaks get very close together as the waves pile up after coming across the deeper lake. There is a knack to handling heavy weather. You don’t want to take the waves directly on the bow or the stern as this will actually lift the outdrives out of the water making it hard to maintain forward progress. I have only stuck the bowsprit into green water a few times

. “Tacking” into the waves to keep them at about 30 degrees from either the bow or the stern creates a rolling motion that can be handled.
And of course, you don't ever want heavy weather directly on the beam.
Several of us are relatively close to your location, so if you would like some reference points or to compare notes before purchase, just let us know.
Rob