For BBC channels all you need is a dish of appropriate size and a digital receiver, dish size probably 1.2m. For ITV channels you will need a Sky digibox and a viewing card, either a free to view card or expired subscription card.
FTV cards are not currently available new. If you subscribe to $ly then the card you get will also allow ITV, C4 and Five reception. When you cancel your subscription (after the minimum 12 months!) the card will still allow reception of these terrestrial channels.
It's possible that the equivqlent of the FTV cards will be made available when $ly launch their own "Freesat" service in the autumn - unfortunately this is far fron certain.
Thanks once again. The other problem I have is that the house we are about to move to is on top of a hill and we get very strong southerly winds. Planning restrictions may not let us mount dish on the building either. Can it be set up at ground level with maybe some kind of shelter round it?