One thing I've never been able to understand is why when the signal is coming from a satellite in the sky do we need a 1.9 dish to receive it.
That is where you are misunderstanding.
UK TV actually comes from 4 satellites, each of these satellites have their own characterisics and transmitting patterns.
In fact if you wanted Sky Sports 1,2 and 3 then you should be OK with a 80 or even a 60 cm dish - as these are transmited from one of the satellite "beams" that is easy to receive. But SSport 4 is on another satellite to 1,2,3 and so reception of SS4 is worse, hence a bigger dish helps reception.
But if you want the free to air versions of BBC1,2,3,4,itv1,2,3,4,C4,e4,m4,five then they are on a satellite with a beam whose reception is poor in Spain, hence big dish.
So you only need a big dish if you want the channels that are on that weaker satellite. I would say that over 50% of the SKy PAY channels are available on a 60-80cm dish over most of Spain.