For free Spanish channels in UK, see:
www.lyngsat.com/freetv/Spain.html .
Astra1 requires only a small dish, Hotbird slightly larger, Hispasat larger still.
(for some idea of dish size, try googling for images of "astra1 footprint", then "hotbird", then "hispasat").
Most inexpensive free-to-air sat receivers will do, but channels do change, to save constant manual updating a "blind scan" type receiver is useful.
A conditional access receiver may allow card viewing of (some) pay channels, depending on how you "get" the card.
A fixed single dish with "monobloc" lnb antenna will get astra1/hotbird, but for receiving 3 or more satellites a motorised dish is really required!
(for suppliers, see our links pages!).