1242 16V inlet will fit.
We used a very early half alloy/half plastic inlet from a Punto Sporting on our 1.4 16V engine as its shorter so better fit in the Seicento engine bay.
therefore I can't think of any reason why your later spec 1.2 16V stuff will not just all bolt on. i think there may only be a few mm differance in TB size, but worth checking, I can't remember exactly but something like 43mm V's 40mm.
Aaron.