Warmoth makes fantasitc stuff, and I think that what you have described would be a beautiful bass. My fretless is a Warmoth neck on a Fender J body, and it is a stunning neck. If you do go with Warmoth, do take advantage of how custom it can be- you have many options such as choosing the shape of the neck- both front and back.
One thought though, I need to side with Toby, if an Alembic is what you want, you may be better served buying a used one while savivng your pennies for the MK. As wonderful as Warmoths are, they take a huge hit when you try to resell them. Since this is a transitional piece, you might better protect your investment by going with the used Alembic. This will also give you some real quality Alembic time, which may grant some insight when the time comes to step up to the plate.
Good luck either way.
Cary