Pro-tip here, if on windows and you want to use a live tv backend that has 1-2 second channel change instead of the terrible speed for native windows backends,install Linux in a vm in windows and run tvheadend from that.I got best results from VMware workstation 9, but you can use virtualbox.
Also a certain chain of stores that you can 'map' all over the country sells a dual tuner for £29' buy 3 of them and you can watch and record every freeview channel at the sametime.(1 mux for each tuner,5 muxes in total for all sd freeview channels, with only 1 tuner you can only watch or record multiple channels on the same mux.)