Ztec turbo89

Hi can any 1 help me i am thinking of buying this engine it has cossie loom but no ecu wich ecu wid i need and i wnt to put it on a zetec s mk5 but am just not to sure about the they key linking up to the ecu .It's an efi this was all in my escort rs turbo
Engine spec:
2.1 zetec turbo
Forged 86mm pistons and steel conrods
New water pump
New cambelt
Aem main bearings
Aem big end bearings
Fully arp/ head gasket head bolts flywheel bolts
Balanced crank new small end bushes and honed to size (Julian Godfrey)
Block modified for oil returns
Block modified for water pump/tensioner block modified for oil drains and reface..
Head...
Stage 3 head ported an polished
Zetec Newman cam
Solid lifters
Vernier adjustable pulley
Inlet ported to match the head no (throttle body)
New alternator/belt.. chrome rocker cover an chrome crossover pipe/ heat wrapped and chrome oil cap I'll leave the tubular manifold on aswell.. Thanks for helping in advance cheers