Morph target structure for animations

I am to the point where I will be adding speech and minor cutscene stuff with the main character, and I have some questions regarding what works and what does not in the structure/setup of the mesh/skeleton.

For all intents and purposes the character works fine as an entire skeletal mesh, but lacks eye expressions and facial movability right now. Obviously.

Plan A: to add facial animations, I am thinking the best way to do it is with morph targets instead of bones. I am guessing that the head will have to be a separate mesh, for this to happen?

Or (Plan B) can I use the original one-piece skeletal mesh and just add morph targets for the head’s vertices? Will this get in the way of the rest of the animation stuff?

Or (Plan C) would it be best to retain the original one-piece character for the in-game action stuff, and then replace it with a separate morph-targeted-head mesh for cutscenes?

If things cannot work using Plan B, and I use Plan A or C, do you have any tips for getting the neck to line up nicely?