the shafts won't fit the sporting, hubs aren't worth the hassle to remove (and means sei is no longer a rolling shell) and if you are turbo'ing the cinq, then you're going to be changing the calipers on that for PuntoGT ones, so another spare set of stock calipers is no use at all.
if it were me then i'd get a second hand 899cc engine and fit that, and sell the lot