ElmBrook

I thought I would chime in as I have chartered, toured and tested a dozen makes / models for the same purpose (just the two of us). A few thoughts for your decision making:
1) do not go smaller than 40' (boats smaller than this are cramped for true liveaboards & not very sea-worthy for the areas you've identified).
2) there good options in the 40' range (new or used). in our case, we had to upgrade to the Leopard 44' just to get sufficient headroom (I am 6'3' and 220 lbs).
3) Dagger boards are not necessary and when not down they'll take up some precious room on board... but with them up, you could beach your Cat.
4) other than budget, the main factor in your decision should be how you envision using it. If you plan on spending many hours inside, then galley, salon, heads, etc. can get quite cramped in most versions under 42' (especially if you are a full sized man). If however you will spend your days above deck or on land, then sailing performance might be a higher priority