I agree with Skip, though I think (and perhaps I am wrong) that it is likely easier to get into the 200 HP range Naturally aspirated with throttle bodies and maybe a Cam in a Duratec than with the Mazda lump and I think it is a touch lighter (all Aluminum).
In the interest of full disclosure I love the Mazda motor, I have one in my Miata. I am working on a Seven but am not sure whether I want a turbo or to keep it NA (would prefer the latter) right now it is set up with an R1 bike motor but still in build stage.
Regards,
T