It does depend on what your meaning of "large" is...
"Large" when compared to the UK dishes may still not be large enough
But for stable UK TV signals via satellite you need a minimum of a 110x120cm dish.
Anything larger will certainly help in the few days of torrential rain we have.
As for internet you have three options:
ADSL -via a landline (Movistar are the BT of Spain and own most of the infrastructure that other adsl companies pay for and use)
Wireless - via a small receiver (companies like Blu, Telitec, Europa and maybe a few others are in the area)
Fiber - if you are one of the lucky ones in a Fiber area