Theys plenty of ways of doing it , from cheap and nasty - thicker head gasket or expensive - machine shop should be able to open up some space in the head but not much ....the best and and 1 of the cheapest ways is a 4k head.
Whats a firing order of a 5k? 1,3,2,4? the mani will be easier than a single turbo :happy: you just got to be clever with the space you got for the SU and the J pipes.
edit : just seen your wanted ad , you in NZ man most of the efi's that are here come from over there! phone your wreckers and look series 60 starlet 1983-1984 came with efi...
I got 1 but its not for sale :happy: