Hello Plug,
A tow vehicle's towed weight limit is based on a series of tests the manufacturer has to perform to get its type approval for sale in the EU. The test uses an idealised trailer, and unfortunately caravans are far from ideal trailers, In fact caravans can produce significant additional loads on a tow vehicle, and to compensate it make a lot of sense to consider a caravan as being somewhat heavier than their specification suggests which points caravanners in the direction of larger tow vehicles.
You tell us you have an caravan with an MTPLM of 1800kg . That is a large caravan. The Industry advice suggests you would need a car with a kerbweight of 1800kg (100% ratio) or 2115k for an 85% match. These are very big cars!
Without knowing what the kerbweight of the Kuga you are looking at, we are not in a position to offer an informed opinion, However Brasso as an owner has suggested most Kuga only have a kerb weight of about 1700Kg, so your towing ratio is already at 106% which is pushing the limits and significantly reducing any safety margin.
I don't know whether it applies to yo, but you couldn't drive this outfit with just a Cat B Licence you need Cat BE.