Another vote for psionic out of the options available.
In the pulp consciousness, psionic has always (for me?) been associated with The East, making this not that much better than "ki", except for being a more socially acceptable solution with _way_ more actual sense behind it (c.f. arguments stating "ki" means "power"...).
Besides that, though, I've always thought the two could be closely related -- the focus that a monk must hold being one of concentration and breathing, with the religious overtones being layered on top of a disciplined mind driving their potent moves. In short, I've always seen the Psionic Warrior/Physical Adept as the Monk.
That said, I'd rather use a third option for both -- Discipline (BDSM jokes aside!), Will, Balance, or Focus, maybe. Those are a bit off the cuff, and I think I prefer Psionics to each of them, but you see what I'm going for.
This brings to mind that there's still a place for the pseudoscience angle of psionics, though... What would you call that powersource?
Phrenics ?
Science! ?