ciao luca,
the repair is possible, you can change the headphone jack - but it is soldered onto the logic board.
i don't know how much ifixit charges for the shipping, but since it's going to italy - it will be not that cheap
i've seen this on ebay many times - most dealers don't ship to italy and swizerland (ok, since switzerland isn't in the eu it requires the whole customs stuff and the shipping costs are horrible)
maybe you should look around in austria or germany - or even ebay italy to find that part.
tje headphone jack from the 2g is the same (as far as the most dealers declare it as the same - looks also the same to me)
does the the headphone jack on your iPod touch work in any way or is it totally dead ?
maybe there is a lint in it (very common)
best regards from germany
markus