Hi Piero
Since no-one else has replied, here's my 0.2 Euros worth.
Defender is a rugged workhorse, not very comfortable but very capable.
Discovery is almost as good off-road (but more shiny bits to worry
about) but much more comfortable over long distances.  If you have not
driven a Defender before, make sure you have a drive in one before
buying as they are quite different from a normal car.  Discoveries are
much more car-like.
On a car of this age, check:
Defender - bulkhead and chassis for rust, engine for smoke and smooth
running.  Everything else can be repaired or replaced at reasonable
cost, but those two represent big expense if they are wrong.
Discovery - rust in bodywork, check especially inside rear doors and
under loadspace floor.  Engines same as Defender.
With all Land Rovers, condition is MUCH more important than mileage.
Service history is good if you can find one with it - at the mileage
you mention, most should have.
Good luck with your search.
And your English is fine - better than some on the group who are native
speakers.  :-) No need to apologise.
Welcome to the group.
Cheers
DaveP