Project Boats -- Where Do You Find Them?
A couple with children sailed around the world in a modified Cal 25. A Cal 27 has full head room--and would make an adequate liveaboard. I lived aboard a Columbia 29 a number of years. I think that in your climate a liveaboard should have a functioning head(or portipotty), adequate heating and insullation (there is a material which is a closed cell PVC foam which is quite cheap and is known as "fish Blanket"--it sticks to a fiberglass hull with liquid nails and makes a nice surface on the interior), full head room, an adequate sleeping platform and at least a table of some sort.
I have both built and restored boats and feel if you have the skills and set a reasonable set of goals you can do well with a restoration--if you start with a solid hull.