If you're talking about direct bolt-on....hell no it won't fit and neither will any of the other Mitsubishi parts. You could adapt them, but jeez itwould be so far from worth while.
Yeah, Garrett has always made a good turbo and with the more recent GT series they just get better. Now that there are lots of other manufacturers the competition is stiffer, but I wouldn't consider MHI(Mitsubishi Heavy Industry) a serious "competitor." Maybe IHI, but even then ther aren't too many non-Japanese makes that are equipped with IHIs. Ford probably got a good price on them due to IHI America's being 50% part of Borg-Warner(hence Warner-Ishi turbos).