punto

hi just wonderin if any one can help i got a mk2 fiat punto it got a 1.2 8v engine. i bought a 1.2 16v sportin lump with the loom and ecu but i heared that i need the keys and ignition barrel which i cant get cos the other car has been scrapped now but if i buy a ecu and barrel with keys will it work ? or is there some thing else i got to do i would be gratfull if some one could help