The reliable diesel engines are real nice. To get an honest four foot draft is an excellent goal. The problem is adequate keel size for this depth. A full hull to four feet will have no keel. Wishing for sails to go upwind at all mandates a true ballast centerboard.
I figured that a true motorsailer is desirable. This means use to sails to assist in reaches and more downwind. Centerboards have a seaworthiness issue. Do you leave them down in a storm to get damaged or not?
A clipper ship hull with almost square rigger performance expected is an idea worthy of consideration. Put in that powerful diesel and use it always.
Get one that self rights also.
The sails in an engine-out scenario could still get you to shore in an emergency. Just anchor of a beach and walk to a telephone. It might take a day of weather weighting to raise the sails but the wait is predictable.
Putting up perfect sail rig with a lame keel costs. The huge rigging does effect self righting negatively. So consider. I think P. Bolger mentioned of these tradeoff considerations.
The small ships of Colvin were self righting I believe. Real nice designs get one.
If you are a low budget self designer please consider my "Litoral Trawler"
There is a thread of mine here. You can not ever expect hulls with chines to self right. My design is ...well it is the lowest cost round bilge trawler hull ever designed. It is easy to use Aluminum for it also.