there's no EFI L20B at all.
there was an EFI L18 though, but good luck finding one.
you'll need a 180B (P610) crossmember, 120Y (B210) castor rods, 180B lower control arms, stanza /180B struts and either the 180B or the 120Y swaybar. that bit eludes me... oh and a 180B master cyl. this should all bolt up to the factory mountings and require no engineering at all.

as far as the gearbox goes, the manual tunnel and the auto tunnel are the same in 1200s, so you can use a TRX blulebird (910) 5 speed behind the L20 with a custom gearbox x-member adaptor plate - this is very very very easy to make.