The only real option right now is to just buy the ST dampers, as I have, since the ST is a half inch lower than other Foci, and those dampers should be up to the demands of handling a higher spring rate and lower ride height.
Konis are a great choice, but I don't think we're going to see a dedicated Mk3 Focus fitment from Koni for a little while. If I had my pick, though, I'd go with Bilsteins.
I've called both companies to get an estimated ETA, and both have given me answers that leave me with no real timeline for expecting product on US shores anytime soon. If anything, we might see something from Bilstein sometime in the next year, as they at least have part numbers listed for the Euro Focus, but good luck finding those parts over here.
The Mazdaspeed3 fitment won't work because the distance from the knuckle to the strut tower is shorter, and the MS3 spring buckets are higher on the strut body. When compared to a Mk3 specific fitment, the MS3 dampers will leave the front of your car sitting higher than it would otherwise.
Joined the dark side.