take out a second hand Sky digibox with Free-to-view card from Sky.
Not necessary, with the exception of pay-per-view channels ANY digital receiver will get the most viewed channels, BBC, ITV, 4 & 5, Film 4 etc. We are using digital receivers from Lidl that cost €25 each. Unlike the crappy old SKY digibox, the Lidl receivers have picture freeze, picture magnify, mosaaic etc., and are really fast. An 80cm dish is a good idea.