In our opinion to be able to watch Freeview reliably you will need two things: firstly you will need a good signal from a wideband aerial; and secondly you will need either an Integrated Digital Television (iDTV, basically a TV with built-in Freeview tuner) or a Freeview set-top box.
For the iDTV or set-top box any high-street electronics retailer will have a wide selection of appropriate choices. Almost all flatscreen TVs are now made with a Freeview tuner built-in with some also having a Freesat tuner as well.
To get an aerial installation that will provide many years of hassle-free viewing you should use a reputable and knowledgable aerial installer who only uses high-quality components and is accredited by the CAI and is a Registered Digital Installer