I'm playing the "Ironborn"-Race(Iron-Heart), and I've thought about becoming undead, but I couldn't find any way to stay a PC with full control.
I´m a Rogue(Unchained) and my best buddy plays a Cleric based on necromancy. So I got the Spells if needed, but I am confused about the Rules, because I couldn't find any rule saying I can, and no one says I can't.
The most-construct body of Ironborns made it more interesting, but I don't know how their body works or how much of their body is organic. Just the beart? A brain? They don't seem to have bones...
Besides ghosts all Undead templates (if it is not a template it is not "you", just a monster inspired by your old body) make you evil if you werent before.
So "full control" you'd only keep if you were evil all along and find a template that doesnt fiddle around in your mental faculties any further. Like instilling hunger for blood or human flesh, or a burning hatred for breathers because just because, or some other crazyness.