It's not so much the 'need' a FMIC, although it would be nice, but basically I believe you can still use the TMIC you have now for just about any application. FMIC's are nice, and greatly reduce the possibility of 'heat soak,' but on the downside they do produce a tad more lag. I'm no expert by any means, but perhaps the extended piping causes this. My friend with the VF30 noticed a difference when he had the Vishnu TMIC and then swtiched to the MRT FMIC.

Regarding specific turbo applications...
I'm not sure on how to answer this question, but, again, referring to what my buddy did with his MY02 WRX, he's pushin the IHI VF30 and is very happy with it. It is pretty much a direct replacement... with all the necessary fuel delivery and EM of course.

-Al-