Im looking at buying one of the flat4online 2.5 engines but im not sure on a few things im hoping theres someone on here who will know.

will my 94 wrx heads fit or will they need work will replace at later date
will my headers fit as they are (mugen)
will my inlet it fit as is
and last 380cc injectors will they be ok for timebeing or would it be best to get bigger in to start with.
i know i will need a remap but is it poss to put my bits on till i can find the

hope someone can help cheers