Only a guess, so you would have to check for sure but Iveco Daily 3.5 tonne and they did do a 5 tonne version with that Sofim engine.
However being RWD not FWD like Ducato then clutch release bearing side may be different.
There was also an uprated engine around 147Bhp used on some models prior to going to the 2.3 and 3 litre DOHC engines on later models.
I don't believe they were known for weak clutches, so is this a seriously overloaded motorhome?
As suggested by @bugsymike I think that a clutch intended for the "2.8jtd power" version with 8143n engine may be worth investigating. Provided that the clutch will fit in the housing, I do not understand the remarks concerning the withdrawal mechanism.
As regards the offering on ebay, why not seek assurance from the supplier?