The quality of the tuner is far more important than where you put it. Having several tuners can also be an advantage re recording - for example, a TV with a good Freeview tuner in plus a DVD recorder/hard-disk recorder with a second strong digital tuner allows you to watch one Freeview channel while recording another at the same time.
Having a good Freeview tuner built into your new flatscreen would be the best starting point (our current, Awards issue gives you plenty of excellent examples) - fewer boxes, connections and remote controls from the off....